#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<ll,ll>;
const int mod = 1e9 + 7;
//const int mod = 998244353;
const ll infll = (1LL << 62) - 1;
const int inf = (1 << 30) - 1;
void YesNo(bool j){cout << (j ? "Yes" : "No") << endl; return;}
void yesno(bool j){cout << (j ? "yes" : "no") << endl; return;}
template<class Head> void pt(Head&& head){cout << head << endl; return;}


int main() {
  int n;
  cin >> n;
  ll ans=0;
  rep(i,n+1) {
      if(i%3!=0 && i%5!=0) ans+=i;
  }
  pt(i);
  return 0;
}