func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 100;   char ch[maxn][maxn];   int main() {     int n;     scanf( %d , &n);     for (int i = 0; i <= n + 1; i++) {       for (int j = 0; j <= n + 1; j++) {         ch[i][j] =  # ;       }     }     for (int i = 1; i <= n; i++) {       getchar();       for (int j = 1; j <= n; j++) {         scanf( %c , &ch[i][j]);       }     }     for (int i = 1; i <= n; i++) {       for (int j = 1; j <= n; j++) {         if (ch[i][j] ==  # ) {           continue;         }         if (ch[i - 1][j] ==  # ) {           continue;         }         if (ch[i][j - 1] ==  # ) {           continue;         }         if (ch[i + 1][j] ==  # ) {           continue;         }         if (ch[i][j + 1] ==  # ) {           continue;         }         ch[i][j] =  # ;         ch[i][j + 1] =  # ;         ch[i][j - 1] =  # ;         ch[i + 1][j] =  # ;         ch[i - 1][j] =  # ;       }     }     bool ans = true;     for (int i = 1; i <= n; i++) {       for (int j = 1; j <= n; j++) {         if (ch[i][j] ==  . ) {           ans = false;         }       }     }     if (ans) {       printf( YES n );     } else {       printf( NO n );     }     return 0;   }   