func_code_string: #include <bits/stdc++.h>   using namespace std;   char a[4][100][100];   int c[6];   int check(int le, int s, char st) {     int ct = 0;     for (int i = 0; i < s; i++) {       for (int j = 0; j < s; j++) {         if ((i - (s - 1) / 2 + j - (s - 1) / 2) % 2 == 0 && a[le][i][j] != st) {           ct++;         } else if ((i - (s - 1) / 2 + j - (s - 1) / 2) % 2 != 0 &&                    a[le][i][j] == st) {           ct++;         }       }     }     return ct;   }   int main() {     int si;     scanf( %d , &si);     getchar();     for (int k = 0; k < 4; k++) {       for (int i = 0; i < si; i++) {         char s[101];         scanf( %s , &s);         for (int r = 0; r < si; r++) a[k][i][r] = s[r];         getchar();       }       if (k != 3) getchar();     }     c[0] = check(0, si,  1 ) + check(1, si,  1 ) + check(2, si,  0 ) +            check(3, si,  0 );     c[1] = check(0, si,  1 ) + check(1, si,  0 ) + check(2, si,  1 ) +            check(3, si,  0 );     c[2] = check(0, si,  1 ) + check(1, si,  0 ) + check(2, si,  0 ) +            check(3, si,  1 );     c[3] = check(0, si,  0 ) + check(1, si,  1 ) + check(2, si,  1 ) +            check(3, si,  0 );     c[4] = check(0, si,  0 ) + check(1, si,  1 ) + check(2, si,  0 ) +            check(3, si,  1 );     c[5] = check(0, si,  0 ) + check(1, si,  0 ) + check(2, si,  1 ) +            check(3, si,  1 );     int ans = 40000;     for (int i = 0; i < 6; i++) {       ans = min(c[i], ans);     }     printf( %d n , ans);     return 0;   }   