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 long[] size = new long[51];
	public static long[] point = new long[51];
	
	public static void main(String[] args){
		size[0] = 1;
		point[0] = 1;
		for (int i = 1; i < 51; i++) {
			size[i] = size[i - 1] * 2 + 3;
			point[i] = point[i - 1] * 2 + 1;
		}
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt(); //整数の入力
		long x = sc.nextLong();
		System.out.println(count(n, x));
		
	}
	
	public static long count(int level, long end) {
		if (level == 0) {
			return 1;
		}
		if (end > size[level]) {
			return point[level];
		}
		long total = 0;
		end--;
		if (end <= 0) {
			return total;
		}
		total += count(level - 1, end);
		end -= size[level - 1];
		if (end <= 0) {
			return total;
		}
		end--;
		total++;
		if (end <= 0) {
			return total;
		}
		total += count(level - 1, end);
		return total;
	}
	
}