N,K=map(int,input().split())
ans=0
P=0
X=K
if 2**N<=K:
	for i in range(N):
		ans+=2**i
	print(ans)
else:
	
	while P<N:
		ans+=X
		if X%2!=0:
			X+=1
		X//=2
		P+=1
		if X==1:
			break
	print(ans+N-P)