"""Starter file for recursion lab."""

def summation(n, term):
    """Return the sum of the 0th to nth terms in the sequence defined
    by term.

    >>> summation(4, lambda x: x*x) # 0 + 1 + 4 + 9 + 16
    30
    """
    "*** YOUR CODE HERE ***"

def gcd(a, b):
    """Return the greatest common divisor of a and b.

    >>> gcd(24, 18)
    6
    >>> gcd(2, 4)
    2
    """
    "*** YOUR CODE HERE ***"

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 paths(m, n):
    "*** YOUR CODE HERE ***"