#include <bits/stdc++.h>
#pragma GCC optimize("O3")

#define fi first
#define se second
#define em emplace
#define eb emplace_back
#define mp make_pair
#define pi pair<int,int>
#define vi vector<int>
#define vpi vector<pair<int,int>>
#define vll vector<ll>
#define vpll vector<pair<ll,ll>>
#define endl '\n'

#define si(v) int(v.size())
#define all(v) v.begin(), v.end()
#define rep(i, n) for (ll i = 0; i < (n); ++i)
#define rep2(i, n, m) for (ll i = n; i <= (m); ++i)
#define rep3(i, n, m) for (ll i = n; i >= (m); --i)

template<class T, class U> bool chmax(T &a, U b) { if (a < b) a = b; return true; }
template<class T, class U> bool chmin(T &a, U b) { if (b < a) a = b; return true; }

using ll = long long;
using ld = long double;
using namespace std;

constexpr ll MOD = 1000000007;

signed main()
{
  cout << fixed << setprecision(20);
  ios::sync_with_stdio(false);
  cin.tie(0);
  
  int a; cin >> a;
  cout << a + a*a + a*a*a << endl;
  
  return (0);
}
#include<bits/stdc++.h>
// Begin Header {{{
using namespace std;
using ll = long long;
using P = pair<ll, ll>;
using Graph = vector<vector<ll>>;
#define rep(i,n) for(ll i=0; i<n; i++)
#define loop(i, j, n) for(ll i=j; i<n; i++)
#define all(x) (x).begin(), (x).end()
constexpr int INF  = 0x3f3f3f40;
const long long mod=2e9+7;
const long double PI = acos(0);
// }}} End Header
int main() {
	ll x, ans=0;
	cin >> x;
	ans+=1000*(x/500);
	x%=500;
	ans+=5*(x/5);
	cout << ans << endl;
	return 0;
}
