# ticket: 480

def f(x):

    return x

def len_f(x):

    """

    >>> len_f([1,2,3])

    3

    """

    return len(f(x))

def float_len_f(x):

    """

    >>> float_len_f([1,2,3])

    3.0

    """

    return float(len(f(x)))

def cast_len_f(x):

    """

    >>> cast_len_f([1,2,3])

    3.0

    """

    return <double>len(f(x))