func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     char c[2] = { w ,  b };     cin >> n;     if (n % 2 == 1)       cout <<  -1 ;     else {       for (int i = 1; i <= n; i++) {         for (int j = 0; j < n; j++) {           for (int k = 0; k < n; k++) {             if ((j / 2) % 2 == 0)               if ((k / 2) % 2 == 0)                 cout << c[i % 2];               else                 cout << c[!(i % 2)];             if ((j / 2) % 2 == 1)               if ((k / 2) % 2 == 0)                 cout << c[!(i % 2)];               else                 cout << c[i % 2];           }           cout << endl;         }         cout << endl;       }     }     return 0;   }   