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