Language: C++

#include<stdio.h>
#include<algorithm>
#include<list>
#include <iterator>

int main(){
    int n, m;
    scanf("%d %d", &n, &m);
    std::list<int> card;
    for(int i = 0; i < n; i++){
        int value;
        scanf("%d", &value);
        card.push_back(value);
    }

    int b[m], c[m];

    for(int i = 0; i < m; i++){
        scanf("%d %d", &b[i], &c[i]);
    }

    for(int i = 0; i < m; i++){
        for(int j = 0; j < b[i]; j++){
            card.push_back(c[i]);
        }
    }

    std::sort(card.begin(), card.end());

    long sum = 0;
    int i = 0;
    auto itr = card.end();
    itr--;
    for(int i = 0; i < n; i++){
        sum += *itr;
        itr--;
    }

    printf("%ld\n", sum);
}

Compiler output:
In file included from /usr/include/c++/14/algorithm:61,
                 from a.cc:2:
/usr/include/c++/14/bits/stl_algo.h: In instantiation of 'void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = _List_iterator<int>; _Compare = __gnu_cxx::__ops::_Iter_less_iter]':
/usr/include/c++/14/bits/stl_algo.h:4772:18:   required from 'void std::sort(_RAIter, _RAIter) [with _RAIter = _List_iterator<int>]'
 4772 |       std::__sort(__first, __last, __gnu_cxx::__ops::__iter_less_iter());
      |       ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:28:14:   required from here
   28 |     std::sort(card.begin(), card.end());
      |     ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:1906:50: error: no match for 'operator-' (operand types are 'std::_List_iterator<int>' and 'std::_List_iterator<int>')
 1906 |                                 std::__lg(__last - __first) * 2,
      |                                           ~~~~~~~^~~~~~~~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:67,
                 from /usr/include/c++/14/algorithm:60:
/usr/include/c++/14/bits/stl_iterator.h:618:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr decltype ((__y.base() - __x.base())) std::operator-(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  618 |     operator-(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:618:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_algo.h:1906:50: note:   'std::_List_iterator<int>' is not derived from 'const std::reverse_iterator<_Iterator>'
 1906 |                                 std::__lg(__last - __first) * 2,
      |                                           ~~~~~~~^~~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1790:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr decltype ((__x.base() - __y.base())) std::operator-(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1790 |     operator-(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1790:5: note:   template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_algo.h:1906:50: note:   'std::_List_iterator<int>' is not derived from 'const std::move_iterator<_IteratorL>'
 1906 |                                 std::__lg(__last - __first) * 2,
      |                                           ~~~~~~~^~~~~~~~~