小猴子下落

#include <iostream>
#include <cstdio>
#include <cmath>

using namespace std;

int main()
{
    int ans=1;
    int d,i;
    while(scanf("%d %d",&d,&i)!=EOF&&(d+i)){
        ans=1;
        for(int j=1;j<d;j++){
            if(i%2==0){
                ans=ans*2+1;
                i/=2;
            }else{
                ans=ans*2;
                i=(i+1)/2;
            }
        }
        printf("%d\n",ans);
    }
    return 0;
}