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
import string
n = raw_input()
n,k = n.split(' ') 

l=[1]
f=[1]
for i in range(55):
    l.append(l[len(l)-1]*2+3)
    f.append(f[len(f)-1]*2+1)

def s(k,level):
    if (level==0):
        if (k>0): return 1
        return 0
    if (k==1): return 0
    if (k>=l[level]): return f[level]
    if (k<l[level]):
        if (k<=l[level-1]+1):
            return s(k-1,level-1)
        if (k==l[level-1]+2):
            return 1+s(k-1,level-1)
        return 1+f[level-1]+s(k-1-1-l[level-1],level-1)

n = string.atoi(n)
k = string.atoi(k)
print (s(k,n))


