#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a, od = 0, ev = 0, ans = 0;
  cin >> n;
  vector<int> vec;
  vector<int>::iterator it;
  while (n--) {
    cin >> a;
    vec.push_back(a);
    if (a % 2 == 0)
      ev++;
    else
      od++;
  }
  for (it = vec.begin(); it != vec.end(); it++) {
    if (ev > od) {
      if (*it % 2 != 0) ans = distance(vec.begin(), it);
    } else if (od > ev) {
      if (*it % 2 == 0) ans = distance(vec.begin(), it);
    }
  }
  cout << ans + 1;
}
