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) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		long x = sc.nextLong();
	    System.out.println(new Barger(n).getCount(x));
   }
   
   static class Barger {
       Barger under;
       int level;
       long size;
       long value;
       
       public Barger(int level) {
           this.level = level;
           if (level == 0) {
               size = 1;
               value = 1;
           } else {
               under = new Barger(level - 1);
               size = under.size * 2 + 3;
               value = under.value * 2 + 1;
           }
       }
       
       public long getCount(long idx) {
           if (level == 0) {
               return 1;
           }
           if (idx < 2) {
               return 0;
           }
           idx--;
           long ans = 0;
           if (idx <= under.size) {
               return under.getCount(idx);
           }
           idx -= under.size;
           ans += under.value;
           if (idx <= 1) {
               return ans + 1;
           }
           idx--;
           ans++;
           if (idx <= under.size) {
               return ans + under.getCount(idx);
           }
           return value;
       }
   }
}


