func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, x[100009], y[100009], sx, sy;   int main() {     cin >> n;     for (int i = 1; i <= n; i++) {       cin >> x[i] >> y[i];       sx += x[i];       sy += y[i];     }     if (sx % 2 == 0 && sy % 2 == 0) {       cout << 0;       return 0;     }     for (int i = 1; i <= n; i++) {       if ((sx - x[i] + y[i]) % 2 == 0 && (sy - y[i] + x[i]) % 2 == 0) {         cout << 1;         return 0;       }     }     cout << -1;   }   