#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define ll long long
#define ld long double
#define ull unsigned long long
#define lcm(a,b) ((a*b)/__gcd(a,b))
const double PI = 2 * acos(0.0);
const int MOD = 1000000007;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    ll n;
    cin >> n;
    int x = n % 500;
    n /= 500;
    int y = x / 5;
    cout << (n * 1000) +  (y * 5) << endl;
}