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

int main() {
  long long int S = 0;
  int N = 0;
  cin >> N;
  for (int i = 1; i < N+1; i++) {
    if ( i%5 != 0 && i%3 != 0 ) {
      S += i;
    }
  }
  cout << S << endl;
}
    
