def main():
    N, M = map(int, input().split())

    ans = 0
    m = M
    for i in range(N):
        if m == 1:
            ans += N - i
            break
        ans += m
        m = (m + 1) // 2

    if m != 1:
        ans = 0
        m = 1
        for _ in range(N):
            ans += m
            m *= 2

    return ans


print(main())