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The puzzle above is an example of a 15-puzzle with the
blank square in the wrong place (bad research!).
The puzzle was the Rubik's cube of Victorian times (read the book Fermat's Last Problem by Simon Singh).
There is a version that is impossible to complete called the 14-15 puzzle.
Jiggle it all around and then try to re-order, it's addictive once you've found a method.