#include <stdio.h>

int main(){
	int n;
	scanf("%d", &n);
	long long int total = 0;
	
	for (int i = 1; i <= n; i++){
		if (i % 3 != 0 && i % 5 != 0){
			total += i;
		}
	}
	printf("%lld", total);

}
#include <bits/stdc++.h>
using ll = long long;
using namespace std;
#define rep(i,n) for(int i=0, i##_len=(int)(n); i<i##_len; i++)
#define reps(i,n) for(int i=1 , i##_len=(int)(n);i<=i##_len;i++)
#define rrep(i,n) for(int i=((int)(n)-1);i>=0;i--)
#define rreps(i,n) for(int i=((int)(n));i>0;i--)
#define repi(i,x) for(auto i=(x).begin(),i##_fin=(x).end();i!=i##_fin;i++)
#define all(x) (x).begin(), (x).end()
#define F first
#define S second
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define eb emplace_back
string solve(bool a) { return ((a) ? "Yes" : "No"); }
typedef vector<int> Vi;
typedef vector<Vi> VVi;
typedef pair<int , int> Pi;
typedef vector<Pi> VPi;
typedef vector<long long> V;
typedef vector<V> VV;
typedef pair<long long , long long> P;
typedef vector<P> VP;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1;} return 0;}
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1;} return 0;}
template <class T, class U>ostream& operator<<(ostream& os, const pair<T, U>& p) {
	os << "(" << p.first << "," << p.second << ")";
	return os;
}
template <class T>ostream& operator<<(ostream& os, const vector<T>& v) {
	os << "{";
	rep(i, v.size()) {
		if (i) os << ",";
		os << v[i];
	}
	os << "}";
	return os;
}
template <class T, class U>istream& operator>>(istream& is, pair<T, U>& p) {
	is >> p.first >>p.second ;
	return is;
}
template <class T>istream& operator>>(istream& is,  vector<T>& v) {
	rep(i, v.size()) {
		is >> v[i];
	}
	return is;
}
const long long INFLL = 1LL<<60;
const int INF = 1<<30;
const double PI=acos(-1);
int main(){
	ll x;
	ll ans=0LL;
	cin >>x;
	ans += x / 500 * 1000;
	x %= 500;
	ans += x / 5 * 5;
	cout<<ans<<endl;
}