'''
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.
Find the sum of all the multiples of 3 or 5 below 1000.
'''
x = 0
for i in range(1000):
	if i%5==0 or i%3==0:
		x = x+i
print(x)
