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{
	public static void main(String[] args){
		long ans = 0;
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long x = sc.nextLong();
		
		long[] all = new long[n+1];
		long n2 = 2;
		for(int i=0; i<=n; i++){
			n2 *= 2;
			all[i] = n2 - 3;
		}
		
		long[] patty = new long[n+1];
		long start = 0;
		for(int i=0; i<=n; i++){
			start = start*2+1;
			patty[i] = start;
		}
		
		long middle = 2;
		for(int i=0; i<n; i++){
			middle *= 2;
		}
		if(x >= middle-1){
			ans = patty[n] - getpnum(n, all[n] - x, all, patty);
		}
		else{
			ans = getpnum(n, x, all, patty);
		}
		
		System.out.println(ans);
	}
	
	static long getpnum(int n, long x, long[] all, long[] patty){
		int med = n;
		int m = 0;
		long ans = 0;
		while(med+all[m] <= x){
			ans = patty[m];
			med--;
			m++;
		}
		if(ans == 0){
			return 0;
		}
		long q = x - (med+1) - all[m-1];
		if(q > 0){
			ans++;
			ans += getpnum(m, q, all, patty);
		}
		
		return ans;
	}
}