func_code_string: #include <bits/stdc++.h>   using namespace std;   char board[2048][2048];   int rows[2][2048];   int cols[2][2048];   int main() {     int N;     scanf( %d , &N);     for (int i = 0; i < N; i++)       for (int j = 0; j < N; j++) scanf(  %c , &board[i][j]);     int ans = 0;     for (int x = 0; x < 2; x++) {       for (int i = 0; i < N - 1; i++)         for (int j = N - 1; j > i; j--) {           int d = rows[x][i] ^ cols[x][j];           if (!d != (board[i][j] ==  0 )) {             ans++;             rows[x][i] ^= 1;             cols[x][j] ^= 1;           }           board[i][j] = board[j][i];         }     }     for (int i = 0; i < N; i++)       if (!(rows[0][i] ^ rows[1][i] ^ cols[0][i] ^ cols[1][i]) !=           (board[i][i] ==  0 ))         ans++;     printf( %d n , ans);     return 0;   }   