import java.util.Scanner;

public class Main {
    public static void main(String[] p) {
        Scanner q = new Scanner(System.in);
        long n = q.nextLong();
        long a = 0L;

        for (long i = 1; i <= n; i++) {
            if (i % 3 == 0 || i % 5 == 0) {
                a += 2L;
            } else if (i % 15 == 0) {
                a += 4;
            }
        }
        System.out.println(a);
    }
}