func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     char arr[100][100];     int m, n, k = 0;     cin >> n >> m;     for (int i = 0; i < n; i++) {       cin >> arr[i];     }     if (m == 1 || n == 1) {       cout << 0;       return 0;     }     for (int i = 0; i < n - 1; i++) {       for (int j = 0; j < m - 1; j++) {         if ( f  != arr[i][j] &&  f  != arr[i + 1][j] &&  f  != arr[i][j + 1] &&              f  != arr[i + 1][j + 1])           continue;         if ( a  != arr[i][j] &&  a  != arr[i + 1][j] &&  a  != arr[i][j + 1] &&              a  != arr[i + 1][j + 1])           continue;         if ( c  != arr[i][j] &&  c  != arr[i + 1][j] &&  c  != arr[i][j + 1] &&              c  != arr[i + 1][j + 1])           continue;         if ( e  != arr[i][j] &&  e  != arr[i + 1][j] &&  e  != arr[i][j + 1] &&              e  != arr[i + 1][j + 1])           continue;         k++;       }     }     cout << k;     return 0;   }   