def f(M):
    X=0
    while M>1:
        M=(M+1)//2
        X+=1
    return X

def g(M):
    X=0
    while M>1:
        X+=M
        M=(M+1)//2
    return X

N,M=map(int,input().split())

if N>f(M):
    Ans=g(M)+1*(N-f(M))
else:
    Ans=0
    A=1
    for _ in range(N):
        Ans+=A
        A*=2

print(Ans)