#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using Graph = vector<vector<int>>;
long long primeNumber(long long x) {
  bool fire = true;
  for(int i = 2; i <= sqrt(x); i++) {
    if(x % i == 0) {
      fire = false;
    }
  }
  return fire;
}
int main() {
  long long N; cin >> N;
  long long x = N/ 3;
  long long y = N / 5;
  long long z = N / 15;
  long long a = (x + y - z - z) * 2ll;
  long long b = z * 4ll;
  cout << a + b << endl;
}