#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <limits>
#include <queue>
#include <iomanip>

using namespace std;
using ll = long long int;
typedef vector<ll> vll;
typedef vector<vll> vvll;
typedef vector<vvll> vvvll;
const int MOD=1000000007;
//const int MOD=998244353;
const int INTMAX=1001001000;
const ll LLMAX=1010010010010010000;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    
    ll N;
    cin>>N;
    
    ll ans=0;
    for(int i=1;i<=N;i++){
        if(i%3!=0 && i%5!=0)ans+=i;
    }
    cout<<ans<<endl;
    
    return 0;
}
