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.*;

class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = Integer.parseInt(sc.next());
		long X = Long.parseLong(sc.next());
		System.out.println(patty(N, X));
	}

	static long patty_sum(int N) {
		return pow(2, N+1)-1;
	}

	static long patty(int N, long X) {
		if (0<=X && X<=1) {
			if (N==0) {
				return 1;
			} else {
				return 0;
			}
		} else if (1<=X && X<=pow(2, N+1)-2) {
			return patty(N-1, X-1);
		} else if (pow(2, N+1)-2<=X && X<=pow(2, N+1)-1) {
			return patty_sum(N-1)+1;
		} else if (pow(2, N+1)-1<=X && X<=pow(2, N+2)-4) {
			return patty_sum(N-1)+1+patty(N-1, X-pow(2, N+1)+1);
		} else {
			return patty_sum(N);
		}
	}

	static long pow(long a,int n) {
	    long res=1;
	    while (n>0) {
	        if ((n-n/2*2)==1) {
	            res=res*a;
	        }
	        a=a*a;
	        n>>=1;
	    }
	    return res;
	}
}