#include <iostream>
#include <map>
#include <unordered_map>
#include <set>
#include <vector>
#include <queue>
#include <algorithm>
#include <cmath>
#include <iomanip>
using namespace std;
#define ll long long
#define PLL pair<ll, ll>
#define PB push_back
#define F first
#define S second
#define MP make_pair
const ll INF = 999999999999999999;
const ll M = 1000000000+7;
int main(){
ll n,k;
cin>>n>>k;
ll index = 1,tpow = 1, m = 1<<n;
k--;
for(ll i=0; i<=n; i++){
//cout<<(k&tpow)<<" "<<tpow<<endl;
if((k&tpow)!=0){
//cout<<(m/tpow)/2<<endl;
index+=(m/tpow)/2;
}
tpow*=2;
}
cout<<index<<endl;
}
