#include <stdio.h>
#include <vector>
#include <algorithm>

std::vector<int> V;
int main()
{
	int a,b;
	scanf("%d%d",&a,&b);
	while(b>1)
	{
		V.push_back(b);
		b = (b+1)/2;
	}
	V.push_back(1);
	std::reverse(V.begin(),V.end());
	if(V.size()<=a)
	{
		long long int sum = 0;
		for(int i=0;i<V.size();i++) sum += V[i];
		sum += (a-V.size());
		printf("%lld",sum);
	}
	else
	{
		long long int sum = 0;
		for(int i=0;i<a;i++) sum += (1<<i);
		printf("%lld",sum);
	}
}