func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAXN = 12;   int rows, cols, k, n;   char mat[MAXN][MAXN];   int sol = 0;   int Calc(int a, int b, int c, int d) {     int ret = 0;     for (int i = a; i <= c; i++) {       for (int j = b; j <= d; j++) ret += (mat[i][j] ==  # );     }     return ret;   }   int main() {     scanf( %d %d %d %d , &rows, &cols, &n, &k);     for (int i = 0; i <= rows; i++)       for (int j = 0; j <= cols; j++) mat[i][j] =  . ;     for (int i = 0; i < n; i++) {       int x, y;       scanf( %d %d , &x, &y);       mat[x][y] =  # ;     }     for (int i = 1; i <= rows; i++) {       for (int j = 1; j <= cols; j++) {         for (int ii = i; ii <= rows; ii++) {           for (int jj = j; jj <= cols; jj++) {             int sum = Calc(i, j, ii, jj);             sol += (sum >= k);           }         }       }     }     printf( %d n , sol);     return 0;   }   