#include<iostream>
using namespace std;

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