#!/usr/bin/env python
# -*- coding: utf-8 -*-

N = int(input())
sm = 0

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

print(sm)