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.
Finish the solution so that it returns the sum of all the multiples of 3 or 5 **below** the number passed in. 
> Note: If the number is a multiple of **both** 3 and 5, only count it *once*.
> Also, if a number is negative, return 0(for languages that do have them)
###### *Courtesy of projecteuler.net*
def solution(number):
  return sum(range(0, number, 3)) + sum(range(0, number, 5)) - sum(range(0, number, 15))
def solution(number):
  return sum(range(0, number, 3)) + sum(range(0, number, 5)) - sum(range(0, number, 15))