package yukicoder;

import java.util.Scanner;

public class N311 {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		long n = sc.nextLong();
		long a = n / 15;
		long b = n / 3;
		long c = n / 5;
		System.out.println((b+c) * 2 + (a - (c/3)) * 4);
	}
}