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

int main() {
	// your code goes here
	int n;
	cin>>n;
	int sum = 0;
	for(int i=0;i<=n;i++)
	{
		if(i%3==0) 
		continue;
		else if(i%5==0)
		continue;
		else
		sum = sum + i;
	}
	cout<<sum;
	
	return 0;
}