#include <bits/stdc++.h>
#define rep(i,n) for(ll (i)=0;(i)<(n);(i)++)
#define repi(i,a,b) for(ll (i)=(a);(i)<(b);(i)++)
#define FOR(i, s, e) for (int i = (int)(s); i <= (int)(e); i++)
#define printYesNo(is_ok) puts(is_ok ? "Yes" : "No");
#define SORT(v) sort(v.begin(), v.end());
#define RSORT(v) sort(v.rbegin(), v.rend());
#define REVERSE(v) reverse(v.begin(), v.end());
typedef long long ll;
using namespace std;
const ll mod = 1e9+7;


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