func_code_string: #include <bits/stdc++.h>   using namespace std;   const int mod = 1e9 + 7;   const long long int INF = 9e18 + 2e17;   const int inf = 2e9;   const int N = 1e5 + 22;   const double eps = 1e-10;   bool cmp(pair<int, int> A, pair<int, int> B) {     if (A.first != B.first) return A.first < B.first;     return A.second > B.second;   }   void _solve() {     int n, m;     cin >> n >> m;     pair<int, int> sr[n];     for (int i = (int)0; i < (int)n; i++) cin >> sr[i].first >> sr[i].second;     sort(sr, sr + n, cmp);     int c = 0;     for (int i = 0; i < n;) {       int x = sr[i].first;       while (i < n && x == sr[i].first) i++;       c++;     }     vector<vector<int> > row_sum(c);     vector<int> tot_sum;     int p = 0;     for (int i = 0; i < n;) {       int x = sr[i].first, sum = 0;       while (i < n && x == sr[i].first) {         sum += sr[i].second;         i++;         if (sum <= 0) continue;         row_sum[p].push_back(sum);       }       if (!row_sum[p].empty()) p++;     }     pair<int, int> row_sz[p];     for (int i = (int)0; i < (int)p; i++) row_sz[i] = {row_sum[i].size(), i};     sort(row_sz, row_sz + p);     for (int y = 0, i = 0; y < p;) {       int x = row_sz[y].first;       while (i < x) {         int sum = 0;         for (int j = (int)y; j < (int)p; j++) sum += row_sum[row_sz[j].second][i];         tot_sum.push_back(sum);         i++;       }       while (x == row_sz[y].first) y++;     }     int ans = 0;     for (int i = (int)0; i < (int)tot_sum.size(); i++) ans = max(ans, tot_sum[i]);     cout << ans;   }   int main() {     ios::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     _solve();     return 0;   }   