#include<bits/stdc++.h>
using namespace std;
bool cmp(long long int x,long long int y)
{
   return x>y;
}
int main(void)
{
   long long int t,n,ans=0;
   vector<long long int> v,v1,v2;
   vector< pair <long long int,long long int> >p,p1,p2;
   set<long long int> st;
   priority_queue<long long int> pq;
   priority_queue< long long int,vector<long long int>,greater<long long int> > lpq;
   priority_queue< pair<long long int,long long int>,vector< pair<long long int,long long int> >,greater< pair <long long int,long long int> > > plpq;
      cin>>n;
      for(long long int i=1;i<=n;i++)
      {
         if(i%3!=0 && i%5!=0)
            ans=ans+i;
      }
      cout<<ans<<endl;
   return 0;
}
