Imagine the full set of dominoes is randomly arranged into 7x8 rectangle. Then the resulting picture is being redrawn in a sheet of paper with all borders between dominoes cleared. You must restore the original configuration.

Of course, not each of 1292697 ways to tile 7x8 rectangle will give the correct solution, but generally, the solution will not be unique.


Martin Gardner claims that this game was designed by Lech Pianowsky. The description of the game was published in one of his Sci. Am. puvlicatons in seventies, or so.