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