import java.util.stream.LongStream;

/**
 * Created by nullzine on 2017/01/20.
 */
public class Main {

    public static void main(String[] args){
        System.out.println(LongStream.range(1,Long.parseLong(new java.util.Scanner(System.in).nextLine())+1).parallel().map(m->m%3==0&&m%5==0?4:(m%3==0||m%5==0?2:0)).sum());
    }

}