using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace kesesigazi
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            int[] ev = Console.ReadLine().Split().Select(int.Parse).ToArray();
            int g = 0;
            for (int i = 0; i < n; i++)
            {
                if (Array.FindIndex(ev, x => x.Equals(ev[i])) == Array.FindLastIndex(ev, x => x.Equals(ev[i])))
                {
                    g = i - 1;
                    break;
                }
            }
            Console.WriteLine(g);
            Console.ReadLine();
        }
    }
}