source_code: import java.util.*;
  
  public class a {
  
  	/**
  	 * @param args
  	 */
  	public static void main(String[] args) {
  		Scanner in = new Scanner(System.in);
  		int n = in.nextInt();
  		int a[] = new int[n];
  		for(int i=0;i<n;i++) a[i] = in.nextInt()%2;
  		
  		int z = 0;
  		for(int i=0;i<n;i++) z+=(a[i] == 0)?1:0;
  		if (z == 1) z = 0;
  		else z = 1;
  		
  		for(int i=0;i<n;i++)
  			if (a[i] == z){
  				System.out.println(i+1);
  				break;
  			}
  	}
  
  }
  