import java.util.stream.LongStream;

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

    public static void main(String[] args) {
        new Main().run2();
    }

    private void run() {
        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());
    }

    private void run2(){
        long n = Long.parseLong(new java.util.Scanner(System.in).nextLine());
        System.out.println((n/3)*2+(n/5)*2);
    }

}