#include <vector> #include <iostream> #include <string> #include <sstream> #include <algorithm> #include <utility> #include <map> #include <cmath> using namespace std; typedef long long ll; typedef pair<ll,ll> P; int main(){ ll n; cin >> n; ll ans = 0; ans += n / 3; ans += n / 5; ans *= 2; cout << ans << endl; }