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

		System.out.println(calculatePatty(N, X));

	}

	public static long calculateBurgerLayerNum(int N) {
		return (long) (Math.pow(2, N + 2) - 3);
	}

	public static long calculatePattyNum(int N) {
		return (long) Math.pow(2, N + 1) - 1;
	}

	public static long calculatePatty(int N, long X) {
		if (X <= N) {
			return 0;
		}
		if (N == 0) {
			return X > 0 ? 1 : 0;
		}

		long burgerLayerNum = calculateBurgerLayerNum(N);
		long burgerLayerHalfNum = burgerLayerNum / 2;
		if (X < burgerLayerHalfNum) {
			long patty = calculatePatty(N - 1, X - 1);
			return patty;
		} else if (X == burgerLayerHalfNum) {
			long pattyNum = calculatePattyNum(N - 1);
			return pattyNum;
		} else if (X == burgerLayerHalfNum + 1) {
			long pattyNum = calculatePattyNum(N - 1);
			return pattyNum + 1;
		} else {
			long patty = calculatePatty(N - 1, X - burgerLayerHalfNum - 1);
			long pattyNum = calculatePattyNum(N - 1);
			return patty + 1 + pattyNum;
		}

	}

}