using System;

public class Program

{

    public static void Main()

    {

        int n = int.Parse(Console.ReadLine());

        string[] input = Console.ReadLine().Split(' ');

        int[] nums = new int[n];

        int countEven = 0;

        int countOdd = 0;

        int lastEvenPos = -1;

        int lastOddPos = -1;

        for(int i = 0; i < n; i++)

        {

            nums[i] = int.Parse(input[i]);

            if(nums[i] % 2 == 0)

            {

                countEven++;

                lastEvenPos = i;

            }

            else

            {

                countOdd++;

                lastOddPos = i;

            }

            if(countEven > 0 && countOdd > 0 && countEven != countOdd)

            {

                if(countEven > countOdd)

                {

                    Console.WriteLine(lastOddPos + 1);

                    break;

                }

                else

                {

                    Console.WriteLine(lastEvenPos + 1);

                    break;

                }

            }

        }

    }

}