Filter with Sort

I have a sheet that list files and folders. In column B if it is a Folder, "<DIR>" will be next to each folder listed in column A. For the files listed in Column A, the file length is shown in Column B. I want to sort the directories first ("<DIR>") and then the files, but the order of the folders must be in alphabetical order first and then all the files must be in alphabetical order and not in size order. That happens if I sort by Column B first

Attached is the file
Sheet1 contains the list, but I want it sorted as on Sheet2