BAM: Very Simple Tile-Sliding Puzzle

[CharlieJV]

Oh - NOW I get it!  The screen at the beginning made me understand.  Still a challenge though.  Nice work - I'll test it out more later today. 

Edit: At least I could solve a 2x2 grid, lol.

- Dav

The beauty of this simple program: it helped me catch a strange little bug with my implementation of SLEEP (and SLEEP 0) to pause the program until user interaction (keyboard press or mouse-click/screen-touch.)