source_code: import java.util.Scanner;
  
  
  
  public class R025A {
  	int n;
  	int[] nums;
  	public R025A() {
  		Scanner scanner = new Scanner(System.in);
  		n = scanner.nextInt();
  		nums = new int[n];
  		for(int i=0; i<n; i++) {
  			nums[i] = scanner.nextInt();
  		}
  	}
  
  	private void process() {
  		int odd = 0;
  		int even = 0;
  		int lastOdd = 0;
  		int lastEven = 0;
  		for(int i=0; i<n; i++) {
  			if(nums[i] % 2 == 0) {
  				even++;
  				lastEven = i+1;
  			} else {
  				odd++;
  				lastOdd = i+ 1;
  			}
  		}
  		if(odd == 1) System.out.println(lastOdd);
  		else System.out.println(lastEven);
  	}
  
  	public static void main(String[] args) {
  		new R025A().process();
  	}
  }
  