func_code_string: #include <bits/stdc++.h>   using namespace std;   char ch[55][55];   int main() {     int n, m;     cin >> n >> m;     for (int i = 0; i < n; i++)       for (int j = 0; j < m; j++) cin >> ch[i][j];     int ret = 0;     for (int i = 0; i < n - 1; i++)       for (int j = 0; j < m - 1; j++) {         bool f = 0, a = 0, c = 0, e = 0;         for (int h = i; h < i + 2; h++)           for (int k = j; k < j + 2; k++)             if (ch[h][k] ==  f )               f = 1;             else if (ch[h][k] ==  a )               a = 1;             else if (ch[h][k] ==  c )               c = 1;             else if (ch[h][k] ==  e )               e = 1;         if (f && a && c && e) ret++;       }     cout << ret << endl;   }   