#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[n + 1];
  int sume = 0, sumo = 0;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    if (a[i] % 2 != 0)
      sumo++;
    else
      sume++;
  }
  for (int i = 1; i <= n; i++) {
    if (sume > sumo) {
      if (a[i] % 2 != 0) {
        cout << i;
        break;
      }
    } else {
      if (a[i] % 2 == 0) {
        cout << i;
        break;
      }
    }
  }
}
