func_code_string: #include <bits/stdc++.h>   using namespace std;   const double eps = 1e-8;   char img[2007][2007];   int c[2007], r[2007];   int main() {     int n;     cin >> n;     for (int i = 0; i < n; i++) scanf( %s , img[i]);     for (int i = 0; i < n; i++)       for (int j = 0; j < n; j++) img[i][j] -=  0 ;     int ans = 0;     for (int i = 0; i < n; i++)       for (int j = n - 1; j > i; --j)         if (c[j] ^ r[i] ^ img[i][j]) {           ++ans;           c[j] ^= 1, r[i] ^= 1;         }     for (int i = 0; i < n; i++) img[i][i] ^= c[i] ^ r[i];     memset(c, 0, sizeof(c)), memset(r, 0, sizeof(r));     for (int i = n - 1; i >= 0; --i)       for (int j = 0; j < i + 1; j++)         if (c[j] ^ r[i] ^ img[i][j]) {           ++ans;           c[j] ^= 1, r[i] ^= 1;         }     cout << ans << endl;     return 0;   }   