foo.cc: In function 'int main()':
foo.cc:14:27: error: request for member 'push_back' in 'v', which is of non-class type 'std::vector<int> [10005]'
   14 |                         v.push_back(y);
      |                           ^~~~~~~~~
foo.cc:17:39: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   17 |                         if(v[x].size()>=y) cout<<v[x][y-1]<<endl;
      |                            ~~~~~~~~~~~^~~
foo.cc:18:38: error: no match for 'operator<' (operand types are 'std::basic_ostream<char>' and '<unresolved overloaded function type>')
   18 |                         else cout<<-1<endl;
      |                              ~~~~~~~~^~~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/regex:66,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:110,
                 from foo.cc:1:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1117:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator<(const sub_match<_BiIter>&, const sub_match<_BiIter>&)'
 1117 |     operator<(const sub_match<_BiIter>& __lhs, const sub_match<_BiIter>& __rhs)
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1117:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1198:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator<(__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&, const sub_match<_BiIter>&)'
 1198 |     operator<(const __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>& __lhs,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1198:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1291:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator<(const sub_match<_BiIter>&, __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&)'
 1291 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1291:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1365:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const typename std::iterator_traits<_Iter>::value_type*, const sub_match<_BiIter>&)'
 1365 |     operator<(typename iterator_traits<_Bi_iter>::value_type const* __lhs,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1365:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   couldn't deduce template parameter '_Bi_iter'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1459:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type*)'
 1459 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1459:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1534:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const typename std::iterator_traits<_Iter>::value_type&, const sub_match<_BiIter>&)'
 1534 |     operator<(typename iterator_traits<_Bi_iter>::value_type const& __lhs,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1534:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   couldn't deduce template parameter '_Bi_iter'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1634:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type&)'
 1634 |     operator<(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1634:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/string:47,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/locale_classes.h:40,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/ios_base.h:41,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/ios:42,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/istream:38,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/sstream:38,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/complex:45,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/ccomplex:39,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:54:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_iterator.h:451:5: note: candidate: 'template<class _Iterator> bool std::operator<(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  451 |     operator<(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_iterator.h:451:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::reverse_iterator<_Iterator>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_iterator.h:496:5: note: candidate: 'template<class _IteratorL, class _IteratorR> bool std::operator<(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  496 |     operator<(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_iterator.h:496:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::reverse_iterator<_Iterator>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_iterator.h:1701:5: note: candidate: 'template<class _IteratorL, class _IteratorR> bool std::operator<(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1701 |     operator<(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_iterator.h:1701:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::move_iterator<_IteratorL>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_iterator.h:1766:5: note: candidate: 'template<class _Iterator> bool std::operator<(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1766 |     operator<(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_iterator.h:1766:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::move_iterator<_IteratorL>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_algobase.h:64,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/string:50:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_pair.h:663:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator<(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
  663 |     operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_pair.h:663:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::pair<_T1, _T2>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/string:53:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/basic_string.h:3699:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const __cxx11::basic_string<_CharT, _Traits, _Alloc>&, const __cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
 3699 |     operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/basic_string.h:3699:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/basic_string.h:3712:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const __cxx11::basic_string<_CharT, _Traits, _Alloc>&, const _CharT*)'
 3712 |     operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/basic_string.h:3712:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/basic_string.h:3724:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator<(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Alloc>&)'
 3724 |     operator<(const _CharT* __lhs,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/basic_string.h:3724:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   mismatched types 'const _CharT*' and 'std::basic_ostream<char>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/deque:64,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:68:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_deque.h:2330:5: note: candidate: 'template<class _Tp, class _Alloc> bool std::operator<(const deque<_Tp, _Alloc>&, const deque<_Tp, _Alloc>&)'
 2330 |     operator<(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y)
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_deque.h:2330:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::deque<_Tp, _Alloc>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/functional:54,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:71:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/tuple:1538:5: note: candidate: 'template<class ... _TElements, class ... _UElements> constexpr bool std::operator<(const tuple<_Elements ...>&, const tuple<_Types ...>&)'
 1538 |     operator<(const tuple<_TElements...>& __t,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/tuple:1538:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::tuple<_Elements ...>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/list:63,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:79:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_list.h:2181:5: note: candidate: 'template<class _Tp, class _Alloc> bool std::operator<(const __cxx11::list<_Tp, _Alloc>&, const __cxx11::list<_Tp, _Alloc>&)'
 2181 |     operator<(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_list.h:2181:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::__cxx11::list<_Tp, _Alloc>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/map:61,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:81:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_map.h:1549:5: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator<(const map<_Key, _Tp, _Compare, _Alloc>&, const map<_Key, _Tp, _Compare, _Alloc>&)'
 1549 |     operator<(const map<_Key, _Tp, _Compare, _Alloc>& __x,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_map.h:1549:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::map<_Key, _Tp, _Compare, _Alloc>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/map:62:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_multimap.h:1170:5: note: candidate: 'template<class _Key, class _Tp, class _Compare, class _Alloc> bool std::operator<(const multimap<_Key, _Tp, _Compare, _Alloc>&, const multimap<_Key, _Tp, _Compare, _Alloc>&)'
 1170 |     operator<(const multimap<_Key, _Tp, _Compare, _Alloc>& __x,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_multimap.h:1170:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::multimap<_Key, _Tp, _Compare, _Alloc>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/memory:75,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:82:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/unique_ptr.h:872:5: note: candidate: 'template<class _Tp, class _Dp, class _Up, class _Ep> bool std::operator<(const unique_ptr<_Tp, _Dp>&, const unique_ptr<_Up, _Ep>&)'
  872 |     operator<(const unique_ptr<_Tp, _Dp>& __x,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/unique_ptr.h:872:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/unique_ptr.h:885:5: note: candidate: 'template<class _Tp, class _Dp> bool std::operator<(const unique_ptr<_Tp, _Dp>&, nullptr_t)'
  885 |     operator<(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/unique_ptr.h:885:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::unique_ptr<_Tp, _Dp>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/unique_ptr.h:895:5: note: candidate: 'template<class _Tp, class _Dp> bool std::operator<(nullptr_t, const unique_ptr<_Tp, _Dp>&)'
  895 |     operator<(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/unique_ptr.h:895:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   couldn't deduce template parameter '_Tp'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr.h:53,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/memory:76:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr_base.h:1840:5: note: candidate: 'template<class _Tp, class _Up, __gnu_cxx::_Lock_policy _Lp> bool std::operator<(const __shared_ptr<_Tp1, _Lp>&, const __shared_ptr<_Tp2, _Lp>&)'
 1840 |     operator<(const __shared_ptr<_Tp, _Lp>& __a,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr_base.h:1840:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::__shared_ptr<_Tp1, _Lp>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr_base.h:1851:5: note: candidate: 'template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator<(const __shared_ptr<_Tp, _Lp>&, nullptr_t)'
 1851 |     operator<(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr_base.h:1851:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::__shared_ptr<_Tp, _Lp>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr_base.h:1859:5: note: candidate: 'template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator<(nullptr_t, const __shared_ptr<_Tp, _Lp>&)'
 1859 |     operator<(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr_base.h:1859:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   couldn't deduce template parameter '_Tp'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr.h:606:5: note: candidate: 'template<class _Tp, class _Up> bool std::operator<(const shared_ptr<_Tp>&, const shared_ptr<_Tp>&)'
  606 |     operator<(const shared_ptr<_Tp>& __a, const shared_ptr<_Up>& __b) noexcept
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr.h:606:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::shared_ptr<_Tp>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr.h:617:5: note: candidate: 'template<class _Tp> bool std::operator<(const shared_ptr<_Tp>&, nullptr_t)'
  617 |     operator<(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr.h:617:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::shared_ptr<_Tp>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr.h:626:5: note: candidate: 'template<class _Tp> bool std::operator<(nullptr_t, const shared_ptr<_Tp>&)'
  626 |     operator<(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr.h:626:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   couldn't deduce template parameter '_Tp'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/vector:64,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/queue:61,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:86:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_vector.h:2074:5: note: candidate: 'template<class _Tp, class _Alloc> bool std::operator<(const vector<_Tp, _Alloc>&, const vector<_Tp, _Alloc>&)'
 2074 |     operator<(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_vector.h:2074:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::vector<_Tp, _Alloc>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/queue:64:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_queue.h:399:5: note: candidate: 'template<class _Tp, class _Seq> bool std::operator<(const queue<_Tp, _Seq>&, const queue<_Tp, _Seq>&)'
  399 |     operator<(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y)
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_queue.h:399:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::queue<_Tp, _Seq>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/set:61,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:87:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_set.h:1023:5: note: candidate: 'template<class _Key, class _Compare, class _Alloc> bool std::operator<(const set<_Key, _Compare, _Alloc>&, const set<_Key, _Compare, _Alloc>&)'
 1023 |     operator<(const set<_Key, _Compare, _Alloc>& __x,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_set.h:1023:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::set<_Key, _Compare, _Alloc>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/set:62:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_multiset.h:1010:5: note: candidate: 'template<class _Key, class _Compare, class _Alloc> bool std::operator<(const multiset<_Key, _Compare, _Alloc>&, const multiset<_Key, _Compare, _Alloc>&)'
 1010 |     operator<(const multiset<_Key, _Compare, _Alloc>& __x,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_multiset.h:1010:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::multiset<_Key, _Compare, _Alloc>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/stack:61,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:89:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_stack.h:375:5: note: candidate: 'template<class _Tp, class _Seq> bool std::operator<(const stack<_Tp, _Seq>&, const stack<_Tp, _Seq>&)'
  375 |     operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y)
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_stack.h:375:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::stack<_Tp, _Seq>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/valarray:603,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:95:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__less, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)'
  419 |     _DEFINE_EXPR_BINARY_OPERATOR(<, struct std::__less)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__less, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)'
  419 |     _DEFINE_EXPR_BINARY_OPERATOR(<, struct std::__less)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__less, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  419 |     _DEFINE_EXPR_BINARY_OPERATOR(<, struct std::__less)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   couldn't deduce template parameter '_Dom'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__less, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)'
  419 |     _DEFINE_EXPR_BINARY_OPERATOR(<, struct std::__less)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__less, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const valarray<typename _Dom::value_type>&, const _Expr<_Dom1, typename _Dom1::value_type>&)'
  419 |     _DEFINE_EXPR_BINARY_OPERATOR(<, struct std::__less)
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   couldn't deduce template parameter '_Dom'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/valarray:1200:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__less, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__less, _Tp>::result_type> std::operator<(const valarray<_Tp>&, const valarray<_Tp>&)'
 1200 | _DEFINE_BINARY_OPERATOR(<, __less)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/valarray:1200:1: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::valarray<_Tp>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/valarray:1200:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__less, std::_ValArray, std::_Constant, _Tp, _Tp>, typename std::__fun<std::__less, _Tp>::result_type> std::operator<(const valarray<_Tp>&, const typename valarray<_Tp>::value_type&)'
 1200 | _DEFINE_BINARY_OPERATOR(<, __less)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/valarray:1200:1: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::valarray<_Tp>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/valarray:1200:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__less, std::_Constant, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__less, _Tp>::result_type> std::operator<(const typename valarray<_Tp>::value_type&, const valarray<_Tp>&)'
 1200 | _DEFINE_BINARY_OPERATOR(<, __less)
      | ^~~~~~~~~~~~~~~~~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/valarray:1200:1: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   couldn't deduce template parameter '_Tp'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:99:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/array:340:5: note: candidate: 'template<class _Tp, long unsigned int _Nm> bool std::operator<(const array<_Tp, _Nm>&, const array<_Tp, _Nm>&)'
  340 |     operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/array:340:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::array<_Tp, _Nm>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/forward_list:38,
                 from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:104:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/forward_list.h:1494:5: note: candidate: 'template<class _Tp, class _Alloc> bool std::operator<(const forward_list<_Tp, _Alloc>&, const forward_list<_Tp, _Alloc>&)'
 1494 |     operator<(const forward_list<_Tp, _Alloc>& __lx,
      |     ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/forward_list.h:1494:5: note:   template argument deduction/substitution failed:
foo.cc:18:39: note:   'std::basic_ostream<char>' is not derived from 'const std::forward_list<_Tp, _Alloc>'
   18 |                         else cout<<-1<endl;
      |                                       ^~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/ios_base.h:46:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/system_error:320:3: note: candidate: 'bool std::operator<(const error_code&, const error_code&)'
  320 |   operator<(const error_code& __lhs, const error_code& __rhs) noexcept
      |   ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/system_error:320:31: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'const std::error_code&'
  320 |   operator<(const error_code& __lhs, const error_code& __rhs) noexcept
      |             ~~~~~~~~~~~~~~~~~~^~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/system_error:502:3: note: candidate: 'bool std::operator<(const error_condition&, const error_condition&)'
  502 |   operator<(const error_condition& __lhs,
      |   ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/system_error:502:36: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'const std::error_condition&'
  502 |   operator<(const error_condition& __lhs,
      |             ~~~~~~~~~~~~~~~~~~~~~~~^~~~~
In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:113:
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/thread:73:3: note: candidate: 'bool std::operator<(thread::id, thread::id)'
   73 |   operator<(thread::id __x, thread::id __y) noexcept
      |   ^~~~~~~~
/nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/thread:73:24: note:   no known conversion for argument 1 from 'std::basic_ostream<char>' to 'std::thread::id'
   73 |   operator<(thread::id __x, thread::id __y) noexcept
      |             ~~~~~~~~~~~^~~

foo.cc: In function 'int main()': foo.cc:14:27: error: request for member 'push_back' in 'v', which is of non-class type 'std::vector<int> [10005]' 14 | v.push_back(y); | ^~~~~~~~~ foo.cc:17:39: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 17 | if(v[x].size()>=y) cout<<v[x][y-1]<<endl; | ~^ foo.cc:18:38: error: no match for 'operator<' (operand types are 'std::basic_ostream<char>' and '<unresolved overloaded function type>') 18 | else cout<<-1<endl; | ^ In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/regex:66, from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:110, from foo.cc:1: /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1117:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator<(const sub_match<_BiIter>&, const sub_match<_BiIter>&)' 1117 | operator<(const sub_match<_BiIter>& __lhs, const sub_match<_BiIter>& __rhs) | ^~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1117:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::__cxx11::sub_match<_BiIter>' 18 | else cout<<-1<endl; | ^~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1198:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator<(__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&, const sub_match<_BiIter>&)' 1198 | operator<(const __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>& __lhs, | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1198:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1291:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator<(const sub_match<_BiIter>&, __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&)' 1291 | operator<(const sub_match<_Bi_iter>& __lhs, | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1291:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::__cxx11::sub_match<_BiIter>' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1365:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const typename std::iterator_traits<_Iter>::value_type*, const sub_match<_BiIter>&)' 1365 | operator<(typename iterator_traits<_Bi_iter>::value_type const* __lhs, | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1365:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: couldn't deduce template parameter '_Bi_iter' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1459:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type*)' 1459 | operator<(const sub_match<_Bi_iter>& __lhs, | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1459:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::__cxx11::sub_match<_BiIter>' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1534:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const typename std::iterator_traits<_Iter>::value_type&, const sub_match<_BiIter>&)' 1534 | operator<(typename iterator_traits<_Bi_iter>::value_type const& __lhs, | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1534:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: couldn't deduce template parameter '_Bi_iter' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1634:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator<(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type&)' 1634 | operator<(const sub_match<_Bi_iter>& __lhs, | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/regex.h:1634:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::__cxx11::sub_match<_BiIter>' 18 | else cout<<-1<endl; | ^~~~ In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-p, _Ep>&)' 872 | operator<(const unique_ptr<_Tp, _Dp>& __x, | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/unique_ptr.h:872:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::unique_ptr<_Tp, _Dp>' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/unique_ptr.h:885:5: note: candidate: 'template<class _Tp, class _Dp> bool std::operator<(const unique_ptr<_Tp, _Dp>&, nullptr_t)' 885 | operator<(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/unique_ptr.h:885:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::unique_ptr<_Tp, _Dp>' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/unique_ptr.h:895:5: note: candidate: 'template<class _Tp, class _Dp> bool std::operator<(nullptr_t, const unique_ptr<_Tp, _Dp>&)' 895 | operator<(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/unique_ptr.h:895:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: couldn't deduce template parameter '_Tp' 18 | else cout<<-1<endl; | ^~~~ In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr.h:53, from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/memory:76: /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr_base.h:1840:5: note: candidate: 'template<class _Tp, class _Up, __gnu_cxx::_Lock_policy _Lp> bool std::operator<(const __shared_ptr<_Tp1, _Lp>&, const __shared_ptr<_Tp2, _Lp>&)' 1840 | operator<(const __shared_ptr<_Tp, _Lp>& __a, | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr_base.h:1840:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::__shared_ptr<_Tp1, _Lp>' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr_base.h:1851:5: note: candidate: 'template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator<(const __shared_ptr<_Tp, _Lp>&, nullptr_t)' 1851 | operator<(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr_base.h:1851:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::__shared_ptr<_Tp, _Lp>' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr_base.h:1859:5: note: candidate: 'template<class _Tp, __gnu_cxx::_Lock_policy _Lp> bool std::operator<(nullptr_t, const __shared_ptr<_Tp, _Lp>&)' 1859 | operator<(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr_base.h:1859:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: couldn't deduce template parameter '_Tp' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr.h:606:5: note: candidate: 'template<class _Tp, class _Up> bool std::operator<(const shared_ptr<_Tp>&, const shared_ptr<_Tp>&)' 606 | operator<(const shared_ptr<_Tp>& __a, const shared_ptr<_Up>& __b) noexcept | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr.h:606:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::shared_ptr<_Tp>' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr.h:617:5: note: candidate: 'template<class _Tp> bool std::operator<(const shared_ptr<_Tp>&, nullptr_t)' 617 | operator<(const shared_ptr<_Tp>& __a, nullptr_t) noexcept | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr.h:617:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::shared_ptr<_Tp>' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr.h:626:5: note: candidate: 'template<class _Tp> bool std::operator<(nullptr_t, const shared_ptr<_Tp>&)' 626 | operator<(nullptr_t, const shared_ptr<_Tp>& __a) noexcept | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/shared_ptr.h:626:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: couldn't deduce template parameter '_Tp' 18 | else cout<<-1<endl; | ^~~~ In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/vector:64, from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/queue:61, from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:86: /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_vector.h:2074:5: note: candidate: 'template<class _Tp, class _Alloc> bool std::operator<(const vector<_Tp, _Alloc>&, const vector<_Tp, _Alloc>&)' 2074 | operator<(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y) | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_vector.h:2074:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::vector<_Tp, _Alloc>' 18 | else cout<<-1<endl; | ^~~~ In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/queue:64: /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_queue.h:399:5: note: candidate: 'template<class _Tp, class _Seq> bool std::operator<(const queue<_Tp, _Seq>&, const queue<_Tp, _Seq>&)' 399 | operator<(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_queue.h:399:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::queue<_Tp, _Seq>' 18 | else cout<<-1<endl; | ^~~~ In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/set:61, from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:87: /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_set.h:1023:5: note: candidate: 'template<class _Key, class _Compare, class _Alloc> bool std::operator<(const set<_Key, _Compare, _Alloc>&, const set<_Key, _Compare, _Alloc>&)' 1023 | operator<(const set<_Key, _Compare, _Alloc>& __x, | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_set.h:1023:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::set<_Key, _Compare, _Alloc>' 18 | else cout<<-1<endl; | ^~~~ In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/set:62: /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_multiset.h:1010:5: note: candidate: 'template<class _Key, class _Compare, class _Alloc> bool std::operator<(const multiset<_Key, _Compare, _Alloc>&, const multiset<_Key, _Compare, _Alloc>&)' 1010 | operator<(const multiset<_Key, _Compare, _Alloc>& __x, | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_multiset.h:1010:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::multiset<_Key, _Compare, _Alloc>' 18 | else cout<<-1<endl; | ^~~~ In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/stack:61, from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:89: /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_stack.h:375:5: note: candidate: 'template<class _Tp, class _Seq> bool std::operator<(const stack<_Tp, _Seq>&, const stack<_Tp, _Seq>&)' 375 | operator<(const stack<_Tp, _Seq>& __x, const stack<_Tp, _Seq>& __y) | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/stl_stack.h:375:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::stack<_Tp, _Seq>' 18 | else cout<<-1<endl; | ^~~~ In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/valarray:603, from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:95: /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom1, class _Dom2> std::_Expr<std::__detail::_BinClos<std::__less, std::_Expr, std::_Expr, _Dom1, _Dom2>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const _Expr<_Dom1, typename _Dom1::value_type>&, const _Expr<_Dom2, typename _Dom2::value_type>&)' 419 | _DEFINE_EXPR_BINARY_OPERATOR(<, struct std::__less) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__less, std::_Expr, std::_Constant, _Dom, typename _Dom::value_type>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const _Expr<_Dom1, typename _Dom1::value_type>&, const typename _Dom::value_type&)' 419 | _DEFINE_EXPR_BINARY_OPERATOR(<, struct std::__less) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__less, std::_Constant, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const typename _Dom::value_type&, const _Expr<_Dom1, typename _Dom1::value_type>&)' 419 | _DEFINE_EXPR_BINARY_OPERATOR(<, struct std::__less) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: couldn't deduce template parameter '_Dom' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__less, std::_Expr, std::_ValArray, _Dom, typename _Dom::value_type>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const _Expr<_Dom1, typename _Dom1::value_type>&, const valarray<typename _Dom::value_type>&)' 419 | _DEFINE_EXPR_BINARY_OPERATOR(<, struct std::__less) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::_Expr<_Dom1, typename _Dom1::value_type>' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: candidate: 'template<class _Dom> std::_Expr<std::__detail::_BinClos<std::__less, std::_ValArray, std::_Expr, typename _Dom::value_type, _Dom>, typename std::__fun<std::__less, typename _Dom1::value_type>::result_type> std::operator<(const valarray<typename _Dom::value_type>&, const _Expr<_Dom1, typename _Dom1::value_type>&)' 419 | _DEFINE_EXPR_BINARY_OPERATOR(<, struct std::__less) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/valarray_after.h:419:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: couldn't deduce template parameter '_Dom' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/valarray:1200:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__less, std::_ValArray, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__less, _Tp>::result_type> std::operator<(const valarray<_Tp>&, const valarray<_Tp>&)' 1200 | _DEFINE_BINARY_OPERATOR(<, __less) | ^~~~~~~~~~~~~~~~~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/valarray:1200:1: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::valarray<_Tp>' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/valarray:1200:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__less, std::_ValArray, std::_Constant, _Tp, _Tp>, typename std::__fun<std::__less, _Tp>::result_type> std::operator<(const valarray<_Tp>&, const typename valarray<_Tp>::value_type&)' 1200 | _DEFINE_BINARY_OPERATOR(<, __less) | ^~~~~~~~~~~~~~~~~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/valarray:1200:1: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::valarray<_Tp>' 18 | else cout<<-1<endl; | ^~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/valarray:1200:1: note: candidate: 'template<class _Tp> std::_Expr<std::__detail::_BinClos<std::__less, std::_Constant, std::_ValArray, _Tp, _Tp>, typename std::__fun<std::__less, _Tp>::result_type> std::operator<(const typename valarray<_Tp>::value_type&, const valarray<_Tp>&)' 1200 | _DEFINE_BINARY_OPERATOR(<, __less) | ^~~~~~~~~~~~~~~~~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/valarray:1200:1: note: template argument deduction/substitution failed: foo.cc:18:39: note: couldn't deduce template parameter '_Tp' 18 | else cout<<-1<endl; | ^~~~ In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:99: /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/array:340:5: note: candidate: 'template<class _Tp, long unsigned int _Nm> bool std::operator<(const array<_Tp, _Nm>&, const array<_Tp, _Nm>&)' 340 | operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b) | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/array:340:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::array<_Tp, _Nm>' 18 | else cout<<-1<endl; | ^~~~ In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/forward_list:38, from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:104: /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/forward_list.h:1494:5: note: candidate: 'template<class _Tp, class _Alloc> bool std::operator<(const forward_list<_Tp, _Alloc>&, const forward_list<_Tp, _Alloc>&)' 1494 | operator<(const forward_list<_Tp, _Alloc>& __lx, | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/forward_list.h:1494:5: note: template argument deduction/substitution failed: foo.cc:18:39: note: 'std::basic_ostream<char>' is not derived from 'const std::forward_list<_Tp, _Alloc>' 18 | else cout<<-1<endl; | ^~~~ In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/bits/ios_base.h:46: /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/system_error:320:3: note: candidate: 'bool std::operator<(const error_code&, const error_code&)' 320 | operator<(const error_code& __lhs, const error_code& __rhs) noexcept | ^~~~~~~~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/system_error:320:31: note: no known conversion for argument 1 from 'std::basic_ostream<char>' to 'const std::error_code&' 320 | operator<(const error_code& __lhs, const error_code& __rhs) noexcept | ~~~~~~~~^ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/system_error:502:3: note: candidate: 'bool std::operator<(const error_condition&, const error_condition&)' 502 | operator<(const error_condition& __lhs, | ^~ /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/system_error:502:36: note: no known conversion for argument 1 from 'std::basic_ostream<char>' to 'const std::error_condition&' 502 | operator<(const error_condition& __lhs, | ~~~~~~~~~~~~~~~~~~~^ In file included from /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-gcc-12.3.0/include/c++/12.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h:113: /nix/store/n8dryz4xf7ln028j37zapgzg4j47p743-