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This is slightly different from Two on Five but is seen as an extension for the highest attaining. You might like to go there first!
The nine cubes are to be connected in the usual way with the following rules being applied.
THE TWO YELLOW CUBES ARE NOT ALLOWED TO TOUCH WALL OR FLOOR SURFACES.
THE THREE BLUE CUBES MUST TOUCH ONE SURFACE ONLY THE WALL OR THE FLOOR
EACH OF THE FOUR RED CUBES MUST TOUCH BOTH WALL AND FLOOR
Here are two examples that obey the rules;