def is_power_of_two(n):
    """Check whether `n` is an exponent of two

    >>> is_power_of_two(0)
    False
    >>> is_power_of_two(1)
    True
    >>> is_power_of_two(2)
    True
    >>> is_power_of_two(3)
    False
    >>> if_power_of_two(16)
    True
    """
    return n != 0 and ((n & (n - 1)) == 0)