#include <bits/stdc++.h>
using namespace std;

int main() {
    int n;
    cin >> n;

    auto sum = 0LL;
    for (int i = 1; i <= n; i++) {
        if (i % 3 == 0)
            continue;
        if (i % 5 == 0)
            continue;
        sum += i;
    }

    cout << sum;
    return 0;
}
