#include<iostream>
#include<cstring>

using namespace std;

int a[205];

int main() {
	int n;
	cin >> n;
	long long sum = 0;
	for (int i = 1; i <= n; ++i) {
		if (i % 3 == 0 || i % 5 == 0) {
			continue;
		}
		else {
			sum += i;
		}
	}
	cout << sum << endl;

	return 0;
}