
#include<algorithm>
#include<bitset>
#include<cmath>
#include<cstdlib>
#include<iomanip>
#include<iostream>
#include<map>
#include<queue>
#include<set>
#include<string>
#include<utility>
#include<vector>

using namespace std;
 
typedef long long ll;

#define PB push_back
#define MP make_pair
#define F first
#define S second

template<typename T,typename U>
bool chmax(T& max, const U& x){
	if(max<x){
		max = x;
		return true;
	}
	return false;
}

template<typename T,typename U>
bool chmin(T& min, const U& x){
	if(min>x){
		min = x;
		return true;
	}
	return false;
}


int main(){
	ll n,ans=0;
  	cin >> n;
  	for(ll i=1;i<=n;i++){
    	if(i%3!=0&&i%5!=0){
        	ans+=i;
        }
    }
  	cout << ans << endl;
}

