#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define int long long
#define all(x) (x).begin(), (x).end()
#define f(i, n) for (int i = 0; i < n; i++)
#define trace(x) cerr << #x << ": " << x << '\n'
int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n;
    cin >> n;
    int c = 0;
    while (n >= 500)
    {
        n -= 500;
        c += 1000;
    }
    cout << c + (n - (n % 5)) << endl;
}