If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.

Write function that take a number n and return the sum of all the multiples of 3 or 5 below n.

def multiples(num): """ >>> multiples(10) # 3 + 5 + 6 + 9 23 """

python