#include <bits/stdc++.h>
using namespace std;

int main(){
	int N,ans = 0;


	cin >> N;

	for (int i = 1; i <= N; i++)
	{
		if(i % 3 == 0 && i %5 == 0){
			ans += 4;
		}else if(i%3 == 0 || i%5 == 0){
			ans += 2;
		}
	}


	cout << ans << endl;




}