#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

int main(void) {
  ll n;
  cin >> n;

  ll a = n / 3, b = n / 5, c = n / 15;
  cout << (a + b - 2 * c) * 2 + c * 4 << endl;

  return 0;
}