#include <bits/stdc++.h>
#include <string>
#include <iostream>
#include <iomanip>
using namespace std;
#define rep(i, N) for (ll i = 0; i < (N); i++)
typedef long long ll;

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