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
// D - Christmas
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

ll f(int n, ll x){
	if(n==0) return x<=0? 0:1;
	ll Ln = (1LL<<n+2) - 3;//L[n]
	ll Pn_1 = (1LL<<n) - 1;//P[n-1]
	ll m = Ln/2 + 1;
	if(m > x) return f(n-1, x-1);
	else if(m < x) return Pn_1 + 1LL + f(n-1, x-m);
	else return Pn_1 + 1LL;
}

int main(){
	int N; ll X; cin>>N>>X;
	cout<< f(N, X) <<endl;
}