#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;
		else if(i%3==0 && i%5!=0) continue;
		else if(i%5==0 && i%3!=0) continue;
		else sum = sum + i;
	}
	cout<<sum;
	return 0;
}
