#include <iostream>
#include <string>
#include <algorithm>
#include <cstdio>
#include <vector>
#include <map>
#include <functional>
#include <cmath>


using namespace std;

int main()
{
	unsigned long long int n,sum = 0;
	cin >> n;

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