import java.util.*;
public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int x = sc.nextInt();
    
    int a = x/500;
    int b = (x%500)/5;
    
    long happy = a*1000 + b*5;

    System.out.println(happy);
    
  }
} import java.util.*; util.* java public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int x = sc.nextInt();
    
    int a = x/500;
    int b = (x%500)/5;
    
    long happy = a*1000 + b*5;

    System.out.println(happy);
    
  }
} Main public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int x = sc.nextInt();
    
    int a = x/500;
    int b = (x%500)/5;
    
    long happy = a*1000 + b*5;

    System.out.println(happy);
    
  } main {
    Scanner sc = new Scanner(System.in);
    int x = sc.nextInt();
    
    int a = x/500;
    int b = (x%500)/5;
    
    long happy = a*1000 + b*5;

    System.out.println(happy);
    
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int x = sc.nextInt(); x sc.nextInt() sc.nextInt sc int a = x/500; a x/500 x 500 int b = (x%500)/5; b (x%500)/5 (x%500) x 500 5 long happy = a*1000 + b*5; happy a*1000 + b*5 a*1000 a 1000 b*5 b 5 System.out.println(happy) System.out.println System.out System System.out happy String[] args args public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int x = sc.nextInt();
    
    int a = x/500;
    int b = (x%500)/5;
    
    long happy = a*1000 + b*5;

    System.out.println(happy);
    
  }
} public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int x = sc.nextInt();
    
    int a = x/500;
    int b = (x%500)/5;
    
    long happy = a*1000 + b*5;

    System.out.println(happy);
    
  }
} Main
import java.util.*;
public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int x = sc.nextInt();
    
    int a = x/500;
    int b = (x%500)/5;
    
    long happy = a*1000 + b*5;

    System.out.println(happy);
    
  }
}