import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);

    int n = sc.nextInt();

    int x_500 =  n/500;
    n = n - n/500 * 500;

    int x_5 = n/5;

    int ans = x_500 *1000 + x_5 * 5;

    System.out.println(ans);

  }
} import java.util.*; util.* java public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);

    int n = sc.nextInt();

    int x_500 =  n/500;
    n = n - n/500 * 500;

    int x_5 = n/5;

    int ans = x_500 *1000 + x_5 * 5;

    System.out.println(ans);

  }
} Main public static void main(String[] args){
    Scanner sc = new Scanner(System.in);

    int n = sc.nextInt();

    int x_500 =  n/500;
    n = n - n/500 * 500;

    int x_5 = n/5;

    int ans = x_500 *1000 + x_5 * 5;

    System.out.println(ans);

  } main {
    Scanner sc = new Scanner(System.in);

    int n = sc.nextInt();

    int x_500 =  n/500;
    n = n - n/500 * 500;

    int x_5 = n/5;

    int ans = x_500 *1000 + x_5 * 5;

    System.out.println(ans);

  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int x_500 =  n/500; x_500 n/500 n 500 n = n - n/500 * 500 n n - n/500 * 500 n n/500 * 500 n/500 n 500 500 int x_5 = n/5; x_5 n/5 n 5 int ans = x_500 *1000 + x_5 * 5; ans x_500 *1000 + x_5 * 5 x_500 *1000 x_500 1000 x_5 * 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){
    Scanner sc = new Scanner(System.in);

    int n = sc.nextInt();

    int x_500 =  n/500;
    n = n - n/500 * 500;

    int x_5 = n/5;

    int ans = x_500 *1000 + x_5 * 5;

    System.out.println(ans);

  }
} public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);

    int n = sc.nextInt();

    int x_500 =  n/500;
    n = n - n/500 * 500;

    int x_5 = n/5;

    int ans = x_500 *1000 + x_5 * 5;

    System.out.println(ans);

  }
} Main
import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);

    int n = sc.nextInt();

    int x_500 =  n/500;
    n = n - n/500 * 500;

    int x_5 = n/5;

    int ans = x_500 *1000 + x_5 * 5;

    System.out.println(ans);

  }
}