'''
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.

Find the sum of all the multiples of 3 or 5 below 1000.
'''


allsum = 0

for i in range(1000):
	if i % 5 == 0:
		allsum = allsum + i
	elif i % 3 == 0:
		allsum = allsum + i

print(allsum)
