#include <bits/stdc++.h>
using namespace std; 
#define lp(var,start,end) for (ll var = start; var <end ; ++var)
#define rlp(var,start,end) for(ll var = start; var>=end ; var--)
#define ios ios_base::sync_with_stdio(false);cin.tie(NULL)
#define ll long long int
#define ld long double
#define fi first 
#define se second 
#define mp make_pair
#define pb push_back
#define ull unsigned long long int
#define vll vector<ll>
#define vld vector<ld>
#define pll pair<ll,ll> 
#define pld pair<ld,ld> 
#define vpll vector<pll>
#define vpld vector<pld>
#define all(X) X.begin(),X.end()
#define mo 1000000007
ll gcd(ll a ,ll b){if(a%b==0)return b;return gcd(b,a%b);}
ll poww(ll a,ll n){if(n==0)return 1;ll p=poww(a,n/2);p=(p*p)%mo;if(n%2)p=(a*p)%mo;return p;}
////////////////////////////////////////////////////

ll tn ; 
void solve()
{
  ll n ; cin>>n ;
  ll sum = 0 ; 
  for(ll i = 1; i<=n; i++)
  {
  	if(n%3&&n%5)
  	sum+=i;
  }
  cout<<sum; 
}
int main()
{ ios; 

ll t ;t = 1; 
  for(tn = 1; tn<=t; tn++)
	solve(); 
	return 0 ; 
}