#include<bits/stdc++.h>
using ll = long long;
using ld = long double;
#define pb push_back
#define ppb pop_back
#define vi vector<int>
#define vll vector<long long>
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define pii pair<int,int>
#define pll pair<ll,ll>
#define F first
#define S second
#define full(n) getline(cin,n)
#define IstiaqModeOn ios::sync_with_stdio(0); cin.tie(0);
using namespace std;
int main()
{
    IstiaqModeOn;
    ll n;
    cin >> n;
    ll nn = n;
    ll festivepoints = ((n/500)*1000) + (((nn%500)/5)*5);
    cout << festivepoints;

}