#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <typeinfo>
#define rep(i, n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int, int>;

int main()
{
    ll n, sum = 0;

    cin >> n;

    for (int i = 1; i <= n; i++)
    {
        sum += (i % 3 != 0 && i % 5 != 0) ? i : 0;
    }
    cout << sum << endl;
}