#include <bits/stdc++.h>
using namespace std;
#define sp " "
#define endl "\n"
#define fileio() freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#define fastio() cin.tie(0), ios_base::sync_with_stdio(0)
#define pb push_back
#define pii pair<int, int>
#define st first
#define nd second
#define N 200005
#define L(node) node * 2
#define R(node) node * 2 + 1
#define int long long
const int modulo = 1e9 + 7;
int n;
int fe(int a, int b)
{
if (b == 0) return 1;
if (b % 2 == 1) return (b * fe(a, b - 1)) % modulo;
int tmp = fe(a, b / 2);
return (tmp * tmp) % modulo;
}
int f(int k, int level)
{
if (level > n) return 1;
int odd = 0;
if (k % (1<<level) == 1) odd = 1;
if (odd) return f(k, level + 1);
return f(k - (1<<(level - 1)), level + 1) + (1<<(n - level));
}
int32_t main()
{
//fileio();
fastio();
int k;
cin>>n>>k;
cout<<f(k, 1)<<endl;
cerr<<"time taken : "<<(float)clock() / CLOCKS_PER_SEC<<" seconds\n";
}
