def euler_sum(n):
    if n <1:
        return 0
    return int(n*(n+1)//2)

def sum_of_multiples_of_3_and_5(n:int) -> None:
    n = n-1
    sum = euler_sum(n//3)*3 + euler_sum(n//5)*5 - euler_sum(n//15)*15
    print(max(sum,0))