def factors(n):
    """
    Return a list of the distinct prime factors of n in nondecreasing order.
    """
    factors = []
    candidate = 2
    while n > 1 and candidate*candidate <= n:
        while n > 1 and n % candidate == 0:
            factors.append(candidate)
	    n = n / candidate
        candidate = candidate + 1
    if n > 1:
        factors.append(n)
    return factors