George rubbed his hands together. "What have you got for me today?" he asked.
I showed him the pieces set up on the chess board and told him the stipulation.
"That's a very strange one." He said. "Where did it come from?"
I told him it was written in 1874 and the name of the author.
"Interesting, interesting. So you can't move the pawns, eh? Mmm. Well, Dijkstra should do it no problem."
Half an hour later, I returned and George proudly announced the answer gesturing grandly at the whiteboard: "Twenty-seven! And there are two ways to do it."
I looked in awe at the whiteboard.
What was the puzzle that I gave George?