import java.util.Scanner;
public class Main{
  public static void main (String args[]){
    Scanner sc = new Scanner(System.in);
    int x = sc.nextInt();
    System.out.print(Logic.run(x));
  }
}
class Logic{
  public static int run(int x){
    int joy = 0;
    joy += (x / 500) * 1000;
    x = x % 500;
    joy += (x / 5) * 5;
    return joy;
  }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz