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 sys
sys.setrecursionlimit(100000000)

N,X=map(int,raw_input().split())

height=[-1]*51
niku=[-1]*51
height[0]=1
niku[0]=1

for i in range(1, N+1):
    height[i]=2*height[i-1]+3
    niku[i]=2*niku[i-1]+1

def rec(l, x):
    if x==1:
        if l==0:
            return 1
        else:
            return 0
    
    if x < 1+height[l-1]+1:
        return rec(l-1, x-1)
    elif x == 1+height[l-1]+1:
        return 1 + niku[l-1]
    elif x <= height[l] - 1:
        return niku[l-1] + 1 + rec(l-1, x-height[l-1]-2)
    else:
        return 2*niku[l-1]+1
print(rec(N, X))



    

