#include<bits/stdc++.h>
using namespace std;
#define FASTIO ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define ll long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pil pair<int,ll>
#define pli pair<ll,int>
#define mod 1000000007
#define mp make_pair
#define pb push_back
#define ff first
#define ss second
ll power(ll a,int n){
  if(n==0)
    return 1;
  if((n%2)==0)
    return power(a*a,n/2);
  else
    return a*power(a*a,n/2);    
}
int main(){
FASTIO 
ll n;
cin>>n;
ll ans=0;
for(ll i=1;i<=n;i++){
   if(((i%3)!=0)&&((i%5)!=0)){
      ans+=i;
   }
}
cout<<ans;
return 0;
}
