package com.company;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
	// write your code here
        Scanner s = new Scanner(System.in);
        int count = 0;
        int N = s.nextInt();
        int FB = N / 15;
        int F = N / 3 - FB;
        int B = N / 5 - FB;
        count = 4 * FB + 2 * (F + B);
        System.out.println(count);
    }
}