func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long mod = 1e9 + 7;   const double eps = 1e-9;   char mapp[110][110];   int main() {     cin.sync_with_stdio(false);     int n, m;     int ans, cnt;     int x1, x2, y1, y2;     while (cin >> n >> m) {       ans = 0;       x1 = 0x3f3f3f3f, x2 = -1, y1 = 0x3f3f3f3f, y2 = -1;       for (int i = 0; i < n; i++) {         for (int j = 0; j < m; j++) {           cin >> mapp[i][j];           if (mapp[i][j] ==  B ) {             x1 = min(x1, i);             y1 = min(y1, j);             x2 = max(x2, i);             y2 = max(y2, j);             ans++;           }         }       }       if (x1 == 0x3f3f3f3f) {         cout << 1 << endl;       } else {         cnt = max(x2 - x1, y2 - y1) + 1;         if (cnt > n || cnt > m) {           cout << -1 << endl;           continue;         }         cout << cnt * cnt - ans << endl;       }     }     return 0;   }   