func_code_string: #include <bits/stdc++.h>   using namespace std;   int a[17][17];   int main() {     int n, m, k, need;     scanf( %d%d%d%d , &n, &m, &k, &need);     for (int i = 1; i <= n; i++) {       for (int j = 1; j <= m; j++) {         int x, y;         scanf( %d%d , &x, &y);         a[x][y] = 1;       }     }     int ans = 0;     for (int x1 = 1; x1 <= n; x1++) {       for (int y1 = 1; y1 <= m; y1++) {         for (int x2 = x1; x2 <= n; x2++) {           for (int y2 = 1; y2 <= m; y2++) {             int tot = 0;             for (int x = x1; x <= x2; x++) {               for (int y = y1; y <= y2; y++) {                 tot += a[x][y];               }             }             if (tot >= need) ans++;           }         }       }     }     printf( %d n , ans);   }   