#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n;
    cin >> n;
    long long int sum = 0;
    for (long long int i = 0; i <= n; i++)
    {
        if (i % 3 == 0 || i % 5 == 0)
        {
            continue;
        }
        sum += i;
    }
    cout << sum << "\n";
    return 0;
}