import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int ans = 0;
        for(int i = 1; i <= n; i++) {
            if(i % 3 == 0 && i % 5 == 0) {
                ans += 4;
            } else if(i % 3 == 0 || i % 5 == 0) {
                ans += 2;
            }
        }
        System.out.println(ans);
    }
}