def hailstone(n):
    """Print out the hailstone sequence starting at n, and return the
    number of elements in the sequence.

    >>> a = hailstone(10)
    10
    5
    16
    8
    4
    2
    1
    >>> a
    7
    """
    "*** YOUR CODE HERE ***"

def symmetric(l):
    """Returns whether a list is symmetric. 
    >>> symmetric([])
    True
    >>> symmetric([1])
    True
    >>> symmetric([1, 4, 5, 1])
    False
    >>> symmetric([1, 4, 4, 1])
    True
    >>> symmetric(['l', 'o', 'l'])
    True
    """
    "*** YOUR CODE HERE ***"