import java.util.*;
public class FizzBuzzString{
	
	static int fi = 4;
	static int tf = 2;

	public static void main(String... args){
		Scanner scan = new Scanner(System.in);
		long n = scan.nextLong();
		long res = 0;
		MyThread th = new MyThread(n);
		for(long i = 1; i <= n; i++){
			if(i%15==0){
				res+=fi;
				continue;
			}else{
				continue;
			}
		}
		th.start();
		System.out.println(res);
	}

}

class MyThread extends Thread{
	long n;
	int fi = 2;
	int res = 0;
	public MyThread(long n){
		this.n = n;
	}

	@Override
	public void run(){
		for(long i = 1; i<= n; i++){
			if(i%3==0 || i%5==0){
				res+=fi;
			}
		}
	}
}