using System;
using System.Linq;
using System.Collections.Generic;

class No123
{
    static void Main()
    {
        var num = Console.ReadLine().Split(' ').Select(x => (Int32.Parse(x))).ToArray();
        var list = Enumerable.Repeat(-1, num[0]).ToList();
        var index = Console.ReadLine().Split(' ').Select(x => (Int32.Parse(x))).ToArray();
        var length = index.Length;
        for (int i = 0; i < length; ++i)
        {
            if (list[index[i]-1] == -1) list.Add(index[i]);
            else
            {
                var n = list[index[i]-1];
                list.Remove(n);
                list.Add(n);
            }
        }
        Console.WriteLine(list.Last() != -1 ? list.Last() : 1);
    }
}