#include<bits/stdc++.h>
using namespace std ;
#define ll long long
#define ld long double
#define ff first
#define ss second
const ll mod =   1e9 +7  ;
ll multiply(ll a, ll b ){ return ((a % mod) * (b % mod)) % mod; }
ll add(ll a, ll b) {     return ((a % mod) + (b % mod)) % mod; }
ll sub(ll a, ll b) { return ((a%mod) - (b % mod)+ mod) % mod ; }
////////////////////////////////////////////////////////////////



///////////////////////////////////////////////////////////////
void solve(){
   int n ;
   cin >> n ;
   ll sum = 0 ;
   for( int i = 1 ; i <=n ; i++){
    if(i%3!=0 && i%5!=0){
        sum+=i;
    }
   }
   cout << sum ;
}
int main(){
    int t = 1 ;
//    cin >> t ;
//    int cnt = 1 ;
    while(t--){
        //cout << "Case #" << cnt << ": ";
        solve( );
      //  cnt++;
    }
}


