def main():
    N, M = map(int, input().split())
    if M < 2 ** (N-1):
        sum_ = M
        value = M
        ctr = 1
        while value > 1:
            match value % 2:
                case 0:
                    value //= 2
                case 1:
                    value = (value // 2) + 1
            ctr += 1
            sum_ += value
        sum_ += (N - ctr)
        print(sum_)
        return

    print(2**N - 1)


if __name__ == "__main__":
    main()