#include <bits/stdc++.h>
using namespace std;

#define pb push_back

#define int ll
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vpii = vector<pii>;
using vvpii = vector<vpii>;

template<typename T>
ostream& operator<<(ostream& o, const vector<T>& v) {
  o << "[";
  for (const T& x : v)
    o << x << ",";
  return o << "]";
}

const int INF = 2e9;

signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);

  int n;
  cin >> n;
  int sum = 0;
  for (int i=0; i<=n; ++i) {
    if (i%3 == 0 || i%5 == 0)
      continue;
    sum += i;
  }
  cout << sum << endl;
}
