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

int main()
{
  long long n;
  cin >> n;

  long long sum = 0;
  for (long long i = 1; i < n; i++)
  {
    if ((i % 3) != 0)
    {
      if ((i%5) != 0)
      {
        sum += i;
      }
    }
    
  }

  cout << sum << endl;
}