func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, m;   char c[109][109];   bool ja = 1;   bool useless = 1;   int main() {     cin >> n >> m;     for (int i = 0; i < n; i++) {       for (int j = 0; j < m; j++) {         cin >> c[i][j];         if (c[i][j] ==  . ) {           if (i % 2 == 0 && j % 2 == 0 || i % 2 == 1 && j % 2 == 1) {             c[i][j] =  B ;           } else {             c[i][j] =  W ;           }         }       }     }     for (int i = 0; i < n; i++) {       for (int j = 0; j < m; j++) {         cout << c[i][j];       }       cout << endl;     }     return 0;   }   