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

typedef long long ll;
typedef long double ld;

#define imx INT_MAX
#define imn INT_MIN
#define llmx LLONG_MAX
#define llmn LLONG_MIN

#define fi first
#define se second
#define pb push_back


int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	int n;
	cin>>n;
	ll sum=0;
	for(int i = 1; i <= n; i++)
	{
		if(!(i%3==0 or i%5==0))
		{
			sum+=i;
		}
	}
	cout<<sum<<endl;
}