import java.util.*;
import java.lang.Math;

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

  }
} import java.util.*; util.* java import java.lang.Math; Math java.lang public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    
   	int num = sc.nextInt();
    int ans = 0;
    
    ans = 1000*(num/500);
    num %= 500;
    ans += num - num%5;
    
    System.out.println(ans);

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

  } main {
    Scanner sc = new Scanner(System.in);
    
   	int num = sc.nextInt();
    int ans = 0;
    
    ans = 1000*(num/500);
    num %= 500;
    ans += num - num%5;
    
    System.out.println(ans);

  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int num = sc.nextInt(); num sc.nextInt() sc.nextInt sc int ans = 0; ans 0 ans = 1000*(num/500) ans 1000*(num/500) 1000 (num/500) num 500 num %= 500 num 500 ans += num - num%5 ans num - num%5 num num%5 num 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 num = sc.nextInt();
    int ans = 0;
    
    ans = 1000*(num/500);
    num %= 500;
    ans += num - num%5;
    
    System.out.println(ans);

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

  }
} Main
import java.util.*;
import java.lang.Math;

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

  }
}
