Line of pawns
8 black pawns and 8 white pawns, alterning on a line.
Group all the black pawns and all the white pawns by
- moving two touching pawns at a time, without reversing,
- set them in contact with at least another pawn.
How many moves are required ?
You may begin with just 4 black pawns and 4 white pawns...
dynamic page allowing to move the pawns by yourself