#include<bits/stdc++.h>
#define rep(i,N) for(ll (i)=0;(i)<(N);(i)++)
#define chmax(x,y) x=max(x,y)
#define chmin(x,y) x=min(x,y)
using namespace std;
typedef long long ll;
typedef pair<int,int> P;
const int mod = 1000000007;
const int INF = 1001001001;

int main() {
  ll n;
  cin >> n;
  ll three = n / 3;
  ll five = n / 5;
  ll threefive =  n / 15;
  three -= threefive; five -= threefive;
  three *= 2;
  five *= 2;
  threefive *= 4;
  ll ans = three + five + threefive;
  cout << ans << endl;
}