
#include <bits/stdc++.h>
using namespace std;
#define fi first
#define endl "\n"
#define se second
#define ls( s) (s&(-s))
#define ll long long
#define inf 0x3f3f3f3f
#define fast    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
const ll N = 500030;
#define rep(i, begin, end) for (__typeof(end) i = (begin) - ((begin) > (end)); i != (end) - ((begin) > (end)); i += 1 - 2 * ((begin) > (end)))
const ll mod =    998244353;


int main()
{  fast
ll  n;
cin>>n;
ll ans=0;
for(ll i=1;i<=n;i++)
{
	if(i%3)
	if(i%5)
	ans+=i;
}
cout<<ans;


}
