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

      int X = sc.nextInt();
      int sum = 0;

      while(X >= 500){
         X -= 500;
         sum += 1000;
      }

      while(X >= 5){
         X -= 5;
         sum += 5;
      }

      System.out.println(sum);
   }
 } 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 sum = 0;

      while(X >= 500){
         X -= 500;
         sum += 1000;
      }

      while(X >= 5){
         X -= 5;
         sum += 5;
      }

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

      int X = sc.nextInt();
      int sum = 0;

      while(X >= 500){
         X -= 500;
         sum += 1000;
      }

      while(X >= 5){
         X -= 5;
         sum += 5;
      }

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

      int X = sc.nextInt();
      int sum = 0;

      while(X >= 500){
         X -= 500;
         sum += 1000;
      }

      while(X >= 5){
         X -= 5;
         sum += 5;
      }

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

      int X = sc.nextInt();
      int sum = 0;

      while(X >= 500){
         X -= 500;
         sum += 1000;
      }

      while(X >= 5){
         X -= 5;
         sum += 5;
      }

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

      int X = sc.nextInt();
      int sum = 0;

      while(X >= 500){
         X -= 500;
         sum += 1000;
      }

      while(X >= 5){
         X -= 5;
         sum += 5;
      }

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

      int X = sc.nextInt();
      int sum = 0;

      while(X >= 500){
         X -= 500;
         sum += 1000;
      }

      while(X >= 5){
         X -= 5;
         sum += 5;
      }

      System.out.println(sum);
   }
 }
