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

class Magatro
{
    static void Main()
    {
        int l = int.Parse(Console.ReadLine());
        int n = int.Parse(Console.ReadLine());
        int[] s = Console.ReadLine().Split(' ').Select(ss => ss.Length).ToArray();
        long cnt = 0;
        for(int i = 0; i < n; i++)
        {
            cnt += (long)Math.Pow(2, l - s[i]);
        }
        Console.WriteLine(cnt);
    }
}