import java.util.*;

class No9002{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		long n = sc.nextInt();
		long cnt = 0;

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