func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, m;   vector<pair<int, int> > a;   long long sum, ans;   int e, deg;   int get_e(int num, int deg) {     if (num == 1) return 0;     if (num == 2) return 1;     int res = num * (num - 1) / 2;     if (deg & 1) {       int bad = num - 2;       res += bad / 2;     }     return res;   }   int main() {     scanf( %d %d , &n, &m);     for (int i = 1; i <= m; i++) {       int q, w;       scanf( %d %d , &q, &w);       a.push_back(make_pair(w, q));     }     sort(a.rbegin(), a.rend());     for (int i = 1; i <= min(3000, m); i++) {       sum += a[i - 1].first;       deg = i - 1;       e = get_e(i, deg);       if (e + 1 <= n) ans = max(ans, sum);     }     cout << ans;     return 0;   }   