using System;
using System.Linq;
using System.Collections.Generic;
public class Hello{
    public static void Main(){

        var n = Console.ReadLine().Split().Select(int.Parse).ToArray();
        
        var cards = new List<int>();
        for(int i=n[0];i>0;i--)
            cards.Add(i);
        
        
        n = Console.ReadLine().Split().Select(int.Parse).ToArray();
        
        for(int i=0;i<n.Length;i++)
        {
            cards.Reverse();
                int tmp=cards[n[i]-1];
                cards.RemoveAt(n[i]-1);
            cards.Reverse();
                cards.Add(tmp);
        }
        
        Console.WriteLine(cards[cards.Count-1]);
    }
}