import java.util.*;

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