#include <bits/stdc++.h>
#define N 1000005
#define int long long
using namespace std;
const int mod = 1e9+7;
int pw(int b){
int ret = 1;
for(int i=0;i<b;i++){
ret = min((int)2e18,ret*2);
}
return ret;
}
int pw2(int b){
int ret = 1;
for(int i=0;i<b;i++){
ret = ret*2%mod;
}
return ret;
}
int get(int n,int k){
if(n == 0)return 1;
int ret = 0;
if(k > pw(n-1)){
ret = 1;
k -= pw(n-1);
}
return 2*get(n-1,k) -1 +ret;
}
void solve(){
int n,k;
cin >> n >> k;
cout << get(n,k);
}
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
#ifdef Local
freopen("in.txt","r",stdin);
freopen("out.txt","w",stdout);
#endif
int t=1;
//cin>>t;
while(t--){
solve();
}
#ifdef Local
cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
#endif
}
