import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner scn = new Scanner(System.in);
        int X = scn.nextInt();
        
        int ans = 0;
        ans += (X/500)*1000;
        X %= 500;
        ans += (X/5)*5;
        System.out.println(ans);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner scn = new Scanner(System.in);
        int X = scn.nextInt();
        
        int ans = 0;
        ans += (X/500)*1000;
        X %= 500;
        ans += (X/5)*5;
        System.out.println(ans);
    }
} Main public static void main(String[] args) throws Exception {
        
        Scanner scn = new Scanner(System.in);
        int X = scn.nextInt();
        
        int ans = 0;
        ans += (X/500)*1000;
        X %= 500;
        ans += (X/5)*5;
        System.out.println(ans);
    } main {
        
        Scanner scn = new Scanner(System.in);
        int X = scn.nextInt();
        
        int ans = 0;
        ans += (X/500)*1000;
        X %= 500;
        ans += (X/5)*5;
        System.out.println(ans);
    } Scanner scn = new Scanner(System.in); scn new Scanner(System.in) int X = scn.nextInt(); X scn.nextInt() scn.nextInt scn int ans = 0; ans 0 ans += (X/500)*1000 ans (X/500)*1000 (X/500) X 500 1000 X %= 500 X 500 ans += (X/5)*5 ans (X/5)*5 (X/5) X 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 scn = new Scanner(System.in);
        int X = scn.nextInt();
        
        int ans = 0;
        ans += (X/500)*1000;
        X %= 500;
        ans += (X/5)*5;
        System.out.println(ans);
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner scn = new Scanner(System.in);
        int X = scn.nextInt();
        
        int ans = 0;
        ans += (X/500)*1000;
        X %= 500;
        ans += (X/5)*5;
        System.out.println(ans);
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner scn = new Scanner(System.in);
        int X = scn.nextInt();
        
        int ans = 0;
        ans += (X/500)*1000;
        X %= 500;
        ans += (X/5)*5;
        System.out.println(ans);
    }
}
