using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using static System.Math;
using static System.Console;


class Program
{
    static long[] sizes = new long[51];

    static void Main()
    {
        long[] NX = ReadLongN();
        long N = NX[0];
        long X = NX[1];

        sizes[0] = 1;
        for (int i = 1; i <= N; i++)
        {
            sizes[i] = 2 * sizes[i - 1] + 3;
        }

        WriteLine(F(N, X));
        ReadLine();
    }

    static long F(long N,long X)
    {
        if (X == 1 && N == 0) return 1;
        else if (X == 1) return 0;
        else if (X > 1 && X < sizes[N] / 2 + 1) return F(N - 1, X - 1);
        else if (X == sizes[N] / 2 + 1) return F(N - 1, sizes[N - 1]) + 1;
        else if (X > sizes[N] / 2 + 1 && X < sizes[N])
        {
            return F(N - 1, sizes[N - 1]) + 1 + F(N - 1, X - (sizes[N] / 2 + 1));
        }
        else return 2 * F(N - 1, sizes[N - 1]) + 1;

    }

    #region Reader
    static string ReadStr()
    {
        return Console.ReadLine();
    }
    static string[] ReadStrN()
    {
        return Console.ReadLine().Split(' ');
    }
    static int ReadInt()
    {
        return Convert.ToInt32(Console.ReadLine());
    }
    static int[] ReadIntN()
    {
        return Console.ReadLine().Split(' ').Select(s => Convert.ToInt32(s)).ToArray();
    }
    static long ReadLong()
    {
        return Convert.ToInt64(Console.ReadLine());
    }
    static long[] ReadLongN()
    {
        return Console.ReadLine().Split(' ').Select(s => Convert.ToInt64(s)).ToArray();
    }
    static long[,] ReadLongMatrix(int r, int c)
    {
        var mat = new long[r, c];
        for (int i = 0; i < r; ++i)
        {
            var x = ReadLongN();
            for (int j = 0; j < c; ++j)
            {
                mat[i, j] = x[j];
            }
        }
        return mat;
    }
    static Tuple<string, string>[] ReadTupleStr(int n)
    {
        List<Tuple<string, string>> list = new List<Tuple<string, string>>();
        for (int i = 0; i < n; ++i)
        {
            var ab = ReadStrN();
            list.Add(new Tuple<string, string>(ab[0], ab[1]));
        }
        return list.ToArray();
    }
    static Tuple<long, long>[] ReadTupleLong(int n)
    {
        List<Tuple<long, long>> list = new List<Tuple<long, long>>();
        for (int i = 0; i < n; ++i)
        {
            var ab = ReadLongN();
            list.Add(new Tuple<long, long>(ab[0], ab[1]));
        }
        return list.ToArray();
    }
    static Tuple<int, int>[] ReadTupleInt(int n)
    {
        List<Tuple<int, int>> list = new List<Tuple<int, int>>();
        for (int i = 0; i < n; ++i)
        {
            var ab = ReadIntN();
            list.Add(new Tuple<int, int>(ab[0], ab[1]));
        }
        return list.ToArray();
    }
    static Tuple<double, double>[] ReadTupleDouble(int n)
    {
        List<Tuple<double, double>> list = new List<Tuple<double, double>>();
        for (int i = 0; i < n; ++i)
        {
            var ab = ReadLongN();
            list.Add(new Tuple<double, double>(ab[0], ab[1]));
        }
        return list.ToArray();
    }
    static Dictionary<int, HashSet<int>> ReadAdjacencyList(int N, int M)
    {
        Dictionary<int, HashSet<int>> dict = new Dictionary<int, HashSet<int>>();
        for (int i = 0; i <= N; ++i)
        {
            dict.Add(i, new HashSet<int>());
        }
        for (int i = 0; i < M; ++i)
        {
            var ab = ReadIntN();
            dict[ab[0]].Add(ab[1]);
            dict[ab[1]].Add(ab[0]);
        }
        return dict;
    }
    #endregion
}

Measured memory_bytes: 13268