//code_sm
#include<bits/stdc++.h>
using namespace std;
#define vi vector<int>
#define si set<int>
#define ll long long
#define pb push_back
int main()
{
	int n;
	cin>>n;
	ll sum=0;
for(int i=1;i<=n;i++)
{
	if(i%3!=0&&i%5!=0)
	sum+=(ll)i;
}
cout<<sum;
}