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 {
	static long eaten;
	static long eatenPatty = 0;
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long level =  Long.parseLong(sc.next());
		eaten = Long.parseLong(sc.next());

		makeBurger(level);

		System.out.println(eatenPatty);
	}

	public static void makeBurger(long level) {
		if(level == 0) {
			if(eaten > 0) {
				eatenPatty ++;
				eaten --;
			}
		}else {
			long gapEaten = 0;
			long gapEatenPatty = 0;
			if(eaten > 0) {
				eaten --;
				long prvEaten = eaten;
				long prvEatenPatty = eatenPatty;
				makeBurger(level - 1);
				gapEaten = eaten - prvEaten;
				gapEatenPatty = eatenPatty - prvEatenPatty;
			}
			if(eaten > 0) {
				eatenPatty ++;
				eaten --;
				if(eaten + gapEaten >= 0) {
					eaten += gapEaten;
					eatenPatty += gapEatenPatty;
				}else {
					makeBurger(level - 1);
				}
			}
			if(eaten > 0) {
				eaten --;
			}
		}
	}
}