func_code_string: #include <bits/stdc++.h>   using namespace std;   string mapp[105];   int main() {     int n, m;     cin >> n >> m;     for (int i = 0; i < n; i++) cin >> mapp[i];     int sx = 0x3f3f3f3f, sy = 0x3f3f3f3f, ex = 0, ey = 0, cnt = 0;     for (int i = 0; i < n; i++) {       for (int j = 0; j < m; j++) {         if (mapp[i][j] ==  B ) {           sx = min(sx, i);           sy = min(sy, j);           ex = max(ex, i);           ey = max(ey, j);           cnt++;         }       }     }     if (cnt == 0) {       cout << 1;       return 0;     }     int len = max(ex - sx + 1, ey - sy + 1);     if (len > n || len > m) {       cout << -1;       return 0;     }     cout << len * len - cnt;     return 0;   }   