import java.util.Scanner;

public class Main {
    public static void main(String args[]){

        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        int result = 0;

        result = result + (X/500)*1000;
        X = X -  (X/500)*500;
        result = result + (X/5)*5;

        System.out.println(result);

    }
} 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 result = 0;

        result = result + (X/500)*1000;
        X = X -  (X/500)*500;
        result = result + (X/5)*5;

        System.out.println(result);

    }
} Main public static void main(String args[]){

        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        int result = 0;

        result = result + (X/500)*1000;
        X = X -  (X/500)*500;
        result = result + (X/5)*5;

        System.out.println(result);

    } main {

        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        int result = 0;

        result = result + (X/500)*1000;
        X = X -  (X/500)*500;
        result = result + (X/5)*5;

        System.out.println(result);

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

        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        int result = 0;

        result = result + (X/500)*1000;
        X = X -  (X/500)*500;
        result = result + (X/5)*5;

        System.out.println(result);

    }
} public class Main {
    public static void main(String args[]){

        Scanner sc = new Scanner(System.in);
        int X = sc.nextInt();
        int result = 0;

        result = result + (X/500)*1000;
        X = X -  (X/500)*500;
        result = result + (X/5)*5;

        System.out.println(result);

    }
} 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 result = 0;

        result = result + (X/500)*1000;
        X = X -  (X/500)*500;
        result = result + (X/5)*5;

        System.out.println(result);

    }
}