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

public class Hello
{
    public static void Main()
    {
        string[] line = Console.ReadLine().Trim().Split(' ');
        var n = int.Parse(line[0]);
        var m = int.Parse(line[1]);
        line = Console.ReadLine().Trim().Split(' ');
        var a = Array.ConvertAll(line, int.Parse);
        var c = new List<int>(n);
        foreach (var x in Enumerable.Range(1, n)) c.Add(x);
        for (int i = 0; i < m; i++)
        {
            var w = c[a[i] - 1];
            c.RemoveAt(a[i] - 1);
            c.Insert(0, w);
        }
        Console.WriteLine(c[0]);
    }
}