func_code_string: #include <bits/stdc++.h>   const int MAXN = 2e6 + 5;   using namespace std;   pair<int, int> arr[MAXN];   bool cmp(const pair<int, int> a, const pair<int, int> b) {     return a.second > b.second;   }   int main() {     int n, m;     scanf( %d %d , &n, &m);     for (int i = 0; i < m; i++) {       int q, w;       scanf( %d %d , &q, &w);       arr[i] = {q, w};     }     sort(arr, arr + m, cmp);     int N = (int(sqrt(8 * n - 7)) + 1) >> 1;     long long ans = 0ll;     int tmp = (N * (N - 1)) >> 1;     if ((N & 1) == 0 && tmp + ((N - 1) >> 1) > n - 1) N--;     for (int i = 0; i < min(N, m); i++) ans += (long long)arr[i].second;     printf( %I64d n , ans);     return 0;   }   