#include <iostream>

using namespace std;

int main(){
	int n;
	cin >> n;
	int cnt = 0;
	for (int i = 1; i <= n; i++){
		if (i % 3 == 0 && i % 5 == 0){
			cnt += 4;
		}
		else if (i % 3 == 0 || i % 5 == 0){
			cnt += 2;
		}
	}
	cout << cnt << endl;
}