#include <iostream>
#include <string>
#include <fstream>
#include <iomanip>
#include <vector>
using namespace std;
static const int MAX_N = 1000005;

int main()
{
	long long n;
	cin >> n;
	cout << 2 * (n / 3 + n / 5) << endl;
	return 0;
}