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