In some other world, today is Christmas.

Mr. Takaha decides to make a multi-dimensional burger in his party. A level-L burger (L is an integer greater than or equal to 0) is the following thing:

* A level-0 burger is a patty.
* A level-L burger (L \geq 1) is a bun, a level-(L-1) burger, a patty, another level-(L-1) burger and another bun, stacked vertically in this order from the bottom.



For example, a level-1 burger and a level-2 burger look like `BPPPB` and `BBPPPBPBPPPBB` (rotated 90 degrees), where `B` and `P` stands for a bun and a patty.

The burger Mr. Takaha will make is a level-N burger. Lunlun the Dachshund will eat X layers from the bottom of this burger (a layer is a patty or a bun). How many patties will she eat?

Constraints

* 1 \leq N \leq 50
* 1 \leq X \leq ( the total number of layers in a level-N burger )
* N and X are integers.

Input

Input is given from Standard Input in the following format:


N X


Output

Print the number of patties in the bottom-most X layers from the bottom of a level-N burger.

Examples

Input

2 7


Output

4


Input

1 1


Output

0


Input

50 4321098765432109


Output

2160549382716056
import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        
        int n = sc.nextInt();
        long x = sc.nextLong();
        
        long[] len = new long[51];
        len[0] = 1L;
        long[] ps = new long[51];
        ps[0] = 1L;
        
        for(int i=0; i<50; i++){
            len[i+1] = len[i]*2+3;
            ps[i+1] = ps[i]*2+1;
        }
        
        long ans = 0L;
        
        for(int i=n; i>=0; i--){
            if(x>=len[i]){
                ans += ps[i];
                x -= len[i];
                if(x > 0){
                    x--;
                    ans++;
                    i++;
                }
            }else{
                x--;
            }
        }
        
        System.out.println(ans);
    }
}