import java.util.*;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		long N = sc.nextLong();

		long cnt1 = 0, cnt2 = 0;
		
		for(long i = 1; i <= N; i++) {
			if(i % 3 == 0) {
				cnt1++;
			}
			if(i % 5 == 0) {
				cnt2++;
			}
		}
		
		System.out.println(cnt1 * 2 + cnt2 * 2);
	}
}