#include <iostream>
using namespace std;
int main(){
  long long n,m;cin>>n>>m;
  long long nw = n;
  long long ans = 0;
  while(m!=1){
    ans += m;
    m=(m+1)/2;
    n--;
    if(!n){
      cout << (1<<nw)-1 << endl;
      return 0;
    }
  }
  cout << ans+n << endl;
}