func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     long long int n;     cin >> n;     long long int a[n], b[n];     long long int sum_1 = 0, sum_2 = 0, c = 0;     for (long long int i = 0; i <= n - 1; i++) {       cin >> a[i] >> b[i];       sum_1 += a[i];       sum_2 += b[i];     }     if (sum_1 % 2 == 0 && sum_2 % 2 == 0) {       cout <<  0  <<   n ;     } else if (n == 1) {       cout <<  -1  <<   n ;     } else {       for (long long int i = 0; i <= n - 1; i++) {         sum_1 -= a[i];         sum_1 += b[i];         sum_2 -= b[i];         sum_2 += a[i];         c++;         if (sum_1 % 2 == 0 && sum_2 % 2 == 0) {           cout << c <<   n ;           return 0;         }         c--;         sum_1 -= b[i];         sum_1 += a[i];         sum_2 -= a[i];         sum_2 += b[i];       }       cout <<  -1  <<   n ;     }     return 0;   }   