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.Scanner;

public class Main {

    private static long rec(int n, long x) {
        if (n == 0) {
            return 1;
        }
        long len = (long) Math.pow(2, n + 1) - 3;
        long num = (long) Math.pow(2, n) - 1;
        if (x == 1) {
            return 0;
        }
        if (x <= len + 1) {
            return rec(n - 1, x - 1);
        }
        if (x <= len + 2) {
            return num + 1;
        }
        if (x <= (len + 1) * 2) {
            return num + 1 + rec(n - 1, x - len - 2);
        }
        return num * 2 + 1;
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        long x = sc.nextLong();
        System.out.println(rec(n, x));
    }
}

