I was also wondering if there is an &#8220;answer sheet&#8221; somewhere?  I got one as a gift for a puzzle nut friend who will love trying to solve these.   Me I would like to give it a shot each morning, but then look it up and change it if I can&#8217;t figure it out before my work day starts.  It&#8217;s like those infinite calendars where you change the month and day blocks, but way more fun (for me).