def f(n, m):
    if n == 1:
        return m
    if n % 2 == 0:
        return n + f(n//2, m - 1)
    else:
        return n + f((n + 1)//2, m - 1)
    

N, M = map(int, input().split())
ans = 2 ** N - 1
print(min(ans, f(M, N)))