#!/usr/bin/env python3

def func(n):
    n = n - 1
    a = n // 3
    b = n // 5
    c = n // 15
    return a*(3 + a*3)//2 + b*(5 + b*5)//2 - c*(15 + c*15)//2

print(func(9))
print(func(10))