import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        int amari = X%500;
        int ans = (X/500)*1000 + (amari/5)*5;
        System.out.println(ans);
        
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        int amari = X%500;
        int ans = (X/500)*1000 + (amari/5)*5;
        System.out.println(ans);
        
    }
} Main public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        int amari = X%500;
        int ans = (X/500)*1000 + (amari/5)*5;
        System.out.println(ans);
        
    } main {
        
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        int amari = X%500;
        int ans = (X/500)*1000 + (amari/5)*5;
        System.out.println(ans);
        
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int X = sc.nextInt(); X sc.nextInt() sc.nextInt sc int amari = X%500; amari X%500 X 500 int ans = (X/500)*1000 + (amari/5)*5; ans (X/500)*1000 + (amari/5)*5 (X/500)*1000 (X/500) X 500 1000 (amari/5)*5 (amari/5) amari 5 5 System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        int amari = X%500;
        int ans = (X/500)*1000 + (amari/5)*5;
        System.out.println(ans);
        
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        int amari = X%500;
        int ans = (X/500)*1000 + (amari/5)*5;
        System.out.println(ans);
        
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        int amari = X%500;
        int ans = (X/500)*1000 + (amari/5)*5;
        System.out.println(ans);
        
    }
}
