source_code: import java.util.Locale;
  import java.util.Scanner;
  
  public class A {
  	public static void main(String[] args) {
  		Locale.setDefault(Locale.US);
  		Scanner sc = new Scanner(System.in);
  		int n = sc.nextInt();
  		String[] number = new String[n];
  		sc.nextLine();
  		String l = sc.nextLine();
  		number = l.split(" ");
  		int oe = 1;
  		if((Integer.valueOf(number[0])%2 +
  		   Integer.valueOf(number[1])%2 +
  		   Integer.valueOf(number[2])%2) > 1) {
  			oe = 0;
  		}
  		for(int i=0;i<n;i++) {
  			if((Integer.valueOf(number[i])%2)==oe) {
  				System.out.println(i+1);
  				break;
  			}
  		}
  	}
  }