In file included from /usr/include/c++/13/bits/stl_algobase.h:71,
                 from /usr/include/c++/13/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/13/bits/stdc++.h:51,
                 from answer.code:1:
/usr/include/c++/13/bits/predefined_ops.h: In instantiation of ‘constexpr bool __gnu_cxx::__ops::_Iter_comp_iter<_Compare>::operator()(_Iterator1, _Iterator2) [with _Iterator1 = int*; _Iterator2 = int*; _Compare = int]’:
/usr/include/c++/13/bits/stl_algo.h:1819:14:   required from ‘void std::__insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<int>]’
/usr/include/c++/13/bits/stl_algo.h:1859:25:   required from ‘void std::__final_insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<int>]’
/usr/include/c++/13/bits/stl_algo.h:1950:31:   required from ‘void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<int>]’
/usr/include/c++/13/bits/stl_algo.h:4894:18:   required from ‘void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = int*; _Compare = int]’
answer.code:62:9:   required from here
/usr/include/c++/13/bits/predefined_ops.h:158:30: error: expression cannot be used as a function
  158 |         { return bool(_M_comp(*__it1, *__it2)); }
      |                       ~~~~~~~^~~~~~~~~~~~~~~~
/usr/include/c++/13/bits/predefined_ops.h: In instantiation of ‘bool __gnu_cxx::__ops::_Val_comp_iter<_Compare>::operator()(_Value&, _Iterator) [with _Value = int; _Iterator = int*; _Compare = int]’:
/usr/include/c++/13/bits/stl_algo.h:1799:20:   required from ‘void std::__unguarded_linear_insert(_RandomAccessIterator, _Compare) [with _RandomAccessIterator = int*; _Compare = __gnu_cxx::__ops::_Val_comp_iter<int>]’
/usr/include/c++/13/bits/stl_algo.h:1827:36:   required from ‘void std::__insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<int>]’
/usr/include/c++/13/bits/stl_algo.h:1859:25:   required from ‘void std::__final_insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<int>]’
/usr/include/c++/13/bits/stl_algo.h:1950:31:   required from ‘void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<int>]’
/usr/include/c++/13/bits/stl_algo.h:4894:18:   required from ‘void std::sort(_RAIter, _RAIter, _Compare) [with _RAIter = int*; _Compare = int]’
answer.code:62:9:   required from here
/usr/include/c++/13/bits/predefined_ops.h:240:30: error: expression cannot be used as a function
  240 |         { return bool(_M_comp(__val, *__it)); }
      |                       ~~~~~~~^~~~~~~~~~~~~~
/usr/include/c++/13/bits/predefined_ops.h: In instantiation of ‘bool __gnu_cxx::__ops::_Iter_comp_val<_Compare>::operator()(_Iterator, _Value&) [with _Iterator = int*; _Value = int; _Compare = int]’:
/usr/include/c++/13/bits/stl_heap.h:140:48:   required from ‘void std::__push_heap(_RandomAccessIterator, _Distance, _Distance, _Tp, _Compare&) [with _RandomAccessIterator = int*; _Distance = long int; _Tp = int; _Compare = __gnu_cxx::__ops::_Iter_comp_val<int>]’
/usr/include/c++/13/bits/stl_heap.h:247:23:   required from ‘void std::__adjust_heap(_RandomAccessIterator, _Distance, _Distance, _Tp, _Compare) [with _RandomAccessIterator = int*; _Distance = long int; _Tp = int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<int>]’
/usr/include/c++/13/bits/stl_heap.h:356:22:   required from ‘void std::__make_heap(_RandomAccessIterator, _RandomAccessIterator, _Compare&) [with _RandomAccessIterator = int*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<int>]’
/usr/include/c++/13/bits/stl_algo.h:1635:23:   required from ‘void std::__heap_select(_RandomAccessIterator, _RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<int>]’
/usr/include/c++/13/bits/stl_algo.h:1910:25:   required from ‘void std::__partial_sort(_RandomAccessIterator, _RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<int>]’
/usr/include/c++/13/bits/stl_algo.h:1926:27:   required from ‘void std::__introsort_loop(_RandomAccessIterator, _RandomAccessIterator, _Size, _Compare) [with _RandomAccessIterator = int*; _Size = long int; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<int>]’
/usr/include/c++/13/bits/stl_algo.h:1947:25:   required from ‘void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = int*; _Compare = __gnu_cxx::__ops::_Iter_comp_iter<int>]’
/usr/incl...