#include <iostream>
using namespace std;

int main() {
	unsigned long N, fizz, buzz, fizzbuzz, count;
	cin >> N;
	fizz = int(N / 3);
	buzz = int(N / 5);
	fizzbuzz = int(N / 15);
	count = fizz + buzz - (fizzbuzz * 2);
	cout << count * 2 + fizzbuzz * 4 << endl;

	return 0;
}