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 {

    static List<Long> plist = new ArrayList<>();
    static List<Long> alllist = new ArrayList<>();
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        long x = sc.nextLong();



        plist.add((long)1);
        alllist.add((long)1);
        for(int i = 1;i <= n;i++){
            plist.add(plist.get(i-1)*2 + 1);
            alllist.add(alllist.get(i-1)*2 + 3);
        }

        System.out.println(calcP(x,n));
    }

    public static long calcP(long x, int n){
        if(x == 0){
            return 0;
        }
        if(n == 0){
            return 1;
        }
        if(x <= alllist.get(n-1)+1){
            return calcP(x-1, n-1);
        } else {
            return plist.get(n-1) + 1 + calcP(x-alllist.get(n-1) -2, n-1);
        }
    }

}