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

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            
            string s1 = Console.ReadLine();
            string[] t1 = s1.Split(' ');
            string s2 = Console.ReadLine();
            string[] t2 = s2.Split(' ');            

            int cardnum = int.Parse(t1[0]);
            int shufflenum = int.Parse(t1[1]);


            int[] stacknum = new int[100000];
            int[] datanum = new int[100000];

            for (int i = 0; i < shufflenum; i++)
            {
                stacknum[i] = int.Parse(t2[i]);
            }

            for (int i = 0; i < cardnum; i++)
            {
                datanum[i] = i + 1;
            }

            for (int i = 0; i < shufflenum; i++)
            {
                int kari = datanum[stacknum[i] - 1];
                int temp = datanum[0];
                int temp2 = 0;
                for (int j = 0; j < stacknum[i] - 1; j++, temp = temp2)
                {
                    temp2 = datanum[j + 1];
                    datanum[j + 1] = temp;
                }
                datanum[0] = kari;
            }

            Console.WriteLine(datanum[0]);
        }
    }
}