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