// Authored by Ibrahimfostok...
// Next level : "Master"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll mod = 998244353;
// const ll mod = 1e9 + 7;
#define gcd __gcd
#define int ll
#define ld long double
#define lcm(a, b) (a * b / gcd(a, b))
#define ceil(x, y) (((x) + (y) - 1ll) / (y))
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define pb push_back
#define MOD(x) x = ((x % mod) + mod) % mod
const long double pi = 3.14159265358979323846;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll rand(ll L, ll R)
{
    return uniform_int_distribution<ll>(L, R)(rng);
}
//
void My_Solve(int TC)
{
    // cout << setprecision(10) << fixed;
    int n;
    cin >> n;
    int ans = n / 500 * 1000;
    n %= 500;
    ans += n / 5 * 5;
    cout << ans;
}
int32_t main()
{
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    // freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stdout);
    int t = 1;
    // cin >> t;
    for (int i = 1; i <= t; i++)
        My_Solve(i);
    return 0;
}