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) throws Exception {
        // Your code here!
        Scanner scan = new Scanner(System.in);
        int N = scan.nextInt();
        long X = scan.nextLong();
        if(N == 0){
            System.out.println(0);
        }
        else{
            System.out.println(Hamb(N,X));
        }
    }
    static long Hamb(int N, long X){
        if(N <= 0){
            return 1;
        }
        long thick = HambThickness(N-1);
        if(X == 1){
            return 0;
        }
        else if(X <= 1 + thick){
            return Hamb(N-1,X-1);
        }
        else if(X == 2 + thick){
            return Patty(N-1)+1;
        }
        else if(X < 2 + 2 * thick){
            return Patty(N-1) + 1 + Hamb(N-1, X - 2 - thick);
        }
        else{
            return 2 * Patty(N-1) + 1;
        }
    }
    static long HambThickness(int N){
        if(N <= 0){
            return 1;
        }
        else{
            return (2 * HambThickness(N-1) + 3);
        }
    }
    static long Patty(int N){
        if(N <= 0){
            return 1;
        }
        else{
            return (2 * Patty(N-1) + 1);
        }
    }
}
