import java.util.Scanner;

public class No311 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long N = sc.nextLong();
		long sum = 0;
		long x;
		x = N/15 * 4;
		sum += (N/3 - x)*2;
		sum += (N/5 - x)*2;
		sum += x * 4;
		System.out.println(sum);
	}
}