As a longtime lurker may I ask a question? I have, I think, the digits of DURATIONS. Or at least, I have 20 “answers” to the clues which are unique four-digit integers and contain distinct nonzero digits. But while I can determine the G value from the BCEF value for each by inspection, I don’t know how to do it in reverse. Do I need to be able to do that? Has anyone solved this without a spreadsheet?