#include<iostream>
using namespace std;

int main(){
  long N,X,ans=0;
  cin>>N>>X;
  if(0<(X>>N-1)){
    cout<<(1L<<N)-1<<endl;
    return 0;
  }
  while(1<X){
    ans+=X,X=(X+1)/2,N--;
  }
  ans+=N;
  cout<<ans<<endl;
}