package no310;

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long ans = 0;
		long n = sc.nextLong();
		long x = n / 15;
		ans += x * 16;
		n -= x * 15;
		for(long i=0;i<n;i++) {
			if (i % 3 == 0) {
				ans += 2;
			}
			if (i % 5 == 0) {
				ans += 2;
			}
		}
		System.out.println(ans);
	}

}