#include <iostream>
using namespace std;

int main() {
	unsigned long long int n;
	int fizzbuzzstring;
	int a, b;
	fizzbuzzstring = 0;
	cin >> n;
	a = n / 3;
	b = n / 5;
	fizzbuzzstring = (a + b) * 2;
	cout << fizzbuzzstring << endl;
	return 0;
}