# -*- coding: utf-8 -*-

N = int(input())

z_counter = 0
for i in range(1, N+1, 1):
    if i%3 == 0 and i%5 == 0:
        z_counter += 4
    elif i%3 == 0 or i%5 == 0:
        z_counter += 2
print(z_counter)