func_code_string: #include <bits/stdc++.h>   using namespace std;   bool within(int x1, int x2, int y1, int y2, int px, int py) {     if (x1 <= px and px <= x2 and y1 <= py and py <= y2) {       return true;     }     return false;   }   int main() {     ios::sync_with_stdio(false);     int y, x, v, n;     cin >> y >> x >> v >> n;     int py[v], px[v];     for (int i = 0; i < v; i++) {       cin >> px[i] >> py[i];       py[i]--, px[i]--;     }     int res = 0;     for (int x1 = 0; x1 < x; x1++) {       for (int x2 = x1; x2 < x; x2++) {         for (int y1 = 0; y1 < y; y1++) {           for (int y2 = y1; y2 < y; y2++) {             int found = 0;             for (int i = 0; i < v; i++) {               if (within(x1, x2, y1, y2, py[i], px[i])) {                 found++;               }             }             if (found >= n) {               res++;             }           }         }       }     }     cout << res;     return 0;   }   