This is a sliding block puzzle that I thought.

+---+---+---+---+---+  
|[N]|[U]|[S]|[H]|[U]|  ［Problem］
+---+---+---+---+---+     Left figure is starting condition.　
|[O]|###|   |###|[G]|   Make a sequence,"GREYHOUNDBUS",with minimum step.
+---+---+---+---+---+　　
|[B]|[Y]|[R]|[D]|[E]|   Note: Vacant room is only one.　
+---+---+---+---+---+         ### are not moved.

If you can get answer, please write it to me or on Cube-Lovers ML.

Toshi(Junk) Kato, Japan 
--------------------------------------JUNK: jkato@tmastb.eec.toshiba.co.jp