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 Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        int N = sc.nextInt();
        long X = sc.nextLong();

        long[] layers = new long[100];
        long[] paties = new long[100];
        layers[0] = 1;
        paties[0] = 1;
        for (int i = 1; i <= N; i++) {
            layers[i] = layers[i-1] * 2L + 3;
            paties[i] = paties[i-1] * 2L + 1;
        }
        System.out.println(paty(N, X, layers, paties));
    }

    private static long paty(int N, long X, long[] layers, long[] paties) {
        if (X == 0) {
            return 0;
        }
        if (N == 0) {
            return 1;
        }
        if (X < layers[N - 1] + 2) {
            return paty(N - 1, X - 1, layers, paties);
        } else {
            return paties[N - 1] + 1 + paty(N - 1, X - layers[N - 1] - 2, layers, paties);
        }
    }
}