#include<bits/stdc++.h>

using namespace std;

#define ll long long
#define all(a) a.begin(),a.end()
#define endl '\n'

int main()
{
    ios::sync_with_stdio(0); cin.tie(0);
    ll n;cin>>n;
    ll ct=1000*(n/500);
    n%=500;
    ct+=5*(n/5);
    cout<<ct<<endl;
        
}