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_less_iter::operator()(_Iterator1, _Iterator2) const [with _Iterator1 = __gnu_cxx::__normal_iterator<node*, std::vector<node> >; _Iterator2 = __gnu_cxx::__normal_iterator<node*, std::vector<node> >]’:
/usr/include/c++/13/bits/stl_algo.h:1819:14:   required from ‘constexpr void std::__insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<node*, vector<node> >; _Compare = __gnu_cxx::__ops::_Iter_less_iter]’
/usr/include/c++/13/bits/stl_algo.h:1859:25:   required from ‘constexpr void std::__final_insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<node*, vector<node> >; _Compare = __gnu_cxx::__ops::_Iter_less_iter]’
/usr/include/c++/13/bits/stl_algo.h:1950:31:   required from ‘constexpr void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<node*, vector<node> >; _Compare = __gnu_cxx::__ops::_Iter_less_iter]’
/usr/include/c++/13/bits/stl_algo.h:4861:18:   required from ‘constexpr void std::sort(_RAIter, _RAIter) [with _RAIter = __gnu_cxx::__normal_iterator<node*, vector<node> >]’
answer.code:24:10:   required from here
/usr/include/c++/13/bits/predefined_ops.h:45:23: error: no match for ‘operator<’ (operand types are ‘node’ and ‘node’)
   45 |       { return *__it1 < *__it2; }
      |                ~~~~~~~^~~~~~~~
In file included from /usr/include/c++/13/bits/stl_algobase.h:67:
/usr/include/c++/13/bits/stl_iterator.h:1189:5: note: candidate: ‘template<class _IteratorL, class _IteratorR, class _Container> constexpr std::__detail::__synth3way_t<_IteratorR, _IteratorL> __gnu_cxx::operator<=>(const __normal_iterator<_IteratorL, _Container>&, const __normal_iterator<_IteratorR, _Container>&)’ (reversed)
 1189 |     operator<=>(const __normal_iterator<_IteratorL, _Container>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/13/bits/stl_iterator.h:1189:5: note:   template argument deduction/substitution failed:
/usr/include/c++/13/bits/predefined_ops.h:45:23: note:   ‘node’ is not derived from ‘const __gnu_cxx::__normal_iterator<_IteratorL, _Container>’
   45 |       { return *__it1 < *__it2; }
      |                ~~~~~~~^~~~~~~~
/usr/include/c++/13/bits/stl_iterator.h:1208:5: note: candidate: ‘template<class _Iterator, class _Container> constexpr std::__detail::__synth3way_t<_T1> __gnu_cxx::operator<=>(const __normal_iterator<_Iterator, _Container>&, const __normal_iterator<_Iterator, _Container>&)’ (rewritten)
 1208 |     operator<=>(const __normal_iterator<_Iterator, _Container>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/13/bits/stl_iterator.h:1208:5: note:   template argument deduction/substitution failed:
/usr/include/c++/13/bits/predefined_ops.h:45:23: note:   ‘node’ is not derived from ‘const __gnu_cxx::__normal_iterator<_Iterator, _Container>’
   45 |       { return *__it1 < *__it2; }
      |                ~~~~~~~^~~~~~~~
/usr/include/c++/13/bits/predefined_ops.h: In instantiation of ‘constexpr bool __gnu_cxx::__ops::_Val_less_iter::operator()(_Value&, _Iterator) const [with _Value = node; _Iterator = __gnu_cxx::__normal_iterator<node*, std::vector<node> >]’:
/usr/include/c++/13/bits/stl_algo.h:1799:20:   required from ‘constexpr void std::__unguarded_linear_insert(_RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<node*, vector<node> >; _Compare = __gnu_cxx::__ops::_Val_less_iter]’
/usr/include/c++/13/bits/stl_algo.h:1827:36:   required from ‘constexpr void std::__insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<node*, vector<node> >; _Compare = __gnu_cxx::__ops::_Iter_less_iter]’
/usr/include/c++/13/bits/stl_algo.h:1859:25:   required from ‘constexpr void std::__final_insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<node*, vector<node> >; _Compare = __gnu_cxx::__ops::_Iter_less_iter]’
/usr/include/c++/13/bits/stl_algo.h:1950:31:   required from ‘constexpr void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator<node*, vector<node> >; _Compare = __gnu_cxx::__ops::_Iter_less_iter]’
/usr/include/c++/13/bits/stl_algo.h:4861:18:   required from ‘constexpr void std::sort(_RAIter, _RAIter) [with _RAIter = __gnu_cxx::__normal_iterator<node*, vector<node> >]’
answer.code:24:10:   required from here
/usr/include/c++/13/bits/predefined_ops.h:98:22: error: no match for ‘operator<’ (o...