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 {
	
  	static long[] all_patty = new long[51];
    static long[] burger_size = new long[51];

    static long calc_burger_size(int level) {
        if (level == 0)
            return 1;
        if (burger_size[level] != 0)
            return burger_size[level];

        return burger_size[level] = 3 + 2 * calc_burger_size(level - 1);
    }

    static long calc_all_patty(int level) {
        if (level == 0)
            return 1;
        if (all_patty[level] != 0)
            return all_patty[level];

        return all_patty[level] = 1 + 2 * calc_all_patty(level - 1);
    }

    static long eat_patty(int level, long X) {
        if (level == 0) {
            return Math.min((long)X, 1L);
        }

        long result = 0L;
        long this_burger_size = calc_burger_size(level);

        if(X >= this_burger_size - 1){
            result =  calc_all_patty(level);
        }else if(X > this_burger_size / 2){
            result =  calc_all_patty(level - 1) + 1 + eat_patty(level - 1, X - this_burger_size / 2 - 1);
        }else if(X > 1L){
            result = eat_patty(level - 1, X - 1);
        }else{
            result = 0L;
        }

        return result;
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = Integer.parseInt(sc.next());
        long X = Long.parseLong(sc.next());
        sc.close();

        all_patty[0] = 1L;
        burger_size[0] = 1L;
        System.out.println(eat_patty(N, X));
    }
}