/* 162-B.cpp
 *     Created on : Apr 12, 2020 
 *     Time       : 6:03:19 PM
 *     Author     : null_ptr
 */
#include<bits/stdc++.h>

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)continue;
		sum+=i;
	}
	cout<<sum;
}



