#include<bits/stdc++.h>
using namespace std;
int main()
{
	long long int N, sum=0;
	cin >> N;
	for(int i=1; i<=N; i++)
	{
		if(i%3 == 0 && i%5 == 0 )
		{
			continue;
		}
		else if(i%3 == 0)
			continue;
		else if(i%5 == 0)
			continue;
		else{
			sum += i;
		}
	}
	cout << sum << endl;
}