# Project Euler
#
# Problem 1
#
# 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.
# 
print("Find the sum of all the multiples of 3 or 5 below 1000.")

n = 0
for i in range (1, 1000):
	if i%5==0 or i%3==0:
		n = n + i
print(n)
