#include <iostream>

using namespace std;

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

    long long sum = 0;

    for (int i = 1; i <= N; ++i) {
        if (i % 3 > 0 && i % 5 > 0) {
            sum += i;
        }
    }

    cout << sum << endl;

    return 0;
}