func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, m, x, y, z;   string str[5][200];   int blcks[5], whites[5];   int ara[] = {0, 1, 2, 3};   int main() {     cin >> n;     for (int i = 0; i < 4; i++) {       for (int j = 0; j < n; j++) cin >> str[i][j];       int tmp = 0;       for (int j = 0; j < n; j++) {         for (int k = 0; k < n; k++) {           if ((j + k) % 2 == 0) {             if (str[i][j][k] ==  0 )               blcks[i]++;             else               whites[i]++;           } else {             if (str[i][j][k] ==  1 )               blcks[i]++;             else               whites[i]++;           }         }       }     }     int ans = 100000000;     do {       int tmp1 = whites[ara[0]] + blcks[ara[1]] + whites[ara[2]] + blcks[ara[3]];       int tmp2 = whites[ara[1]] + blcks[ara[0]] + whites[ara[3]] + blcks[ara[2]];       ans = min(ans, tmp1);       ans = min(ans, tmp2);     } while (next_permutation(ara, ara + 4));     cout << ans << endl;     return 0;   }   