#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(n);++i)
#define all(a) (a).begin(),(a).end()
#define dunk(a) cout << (a) << endl
using namespace std;
typedef long long ll;

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	ll n;
	cin >> n;

	ll res1 = 0;
	ll res2 = 0;
	
	res1 = n / 3;

	res2 = n / 5;

	ll ans = (res1 + res2) * 2;

	dunk(ans);

	return 0;
}