#include <iostream>

using namespace std;
typedef unsigned long long ullong;

int main(int argc, char** argv)
{
	ullong N; cin >> N;
	ullong ans = 0;
	ans += (N/15) * 16;
	ans += (N%15/3) * 2;
	ans += (N%15/5) * 2;
	cout << ans << endl;
	return 0;
}