#include <iostream>

using namespace std;

int main(int argc, const char* argv[])
{
	size_t N;
	cin >> N;
	size_t cnt = 0;
	for (size_t i = 1; i <= N; i++) {
		if (i % 3 == 0) cnt += 2;
		if (i % 5 == 0) cnt += 2;
	}
	cout << cnt << endl;
	return 0;
}