#include <bits/stdc++.h>
#define PI 3.14159265359
using namespace std;
const int64_t mod = 1e9 + 7;

int main() {
	int64_t N;
	cin >> N;

	int64_t fb, f, b;
	fb = N / 15;
	f = N / 3 - fb;
	b = N / 5 - fb;

	cout << 4 * fb + 2 * (f + b) << endl;
}