#include <bits//stdc++.h>
using namespace std;
#define int long long
#define rep(i,n,k) for(int i=n;i<k;i++)
#define P make_pair
#define F first
#define S second
#define M LLONG_MAX
signed main(void){
    int n,m,ans,w,p,q;
    ans=0;
    string s,s1,s2;
    vector<int> v;
   cin>>n;
   rep(i,1,n+1){
       if(i%3!=0&&i%5!=0)
       ans+=i;
   }
   cout<<ans<<endl;
   
}
