Colour some cells to create a continuous shape that contains no 2x2 square. Numbers in a cell denote the lengths of the sequences of connected neighbouring coloured cells when looking at its (at most 8) direct neighbours only. If there is more than one number in a square, there must be at least one white cell between the coloured cell sequences. Cells containing a number should not be coloured. Question marks that occur in some puzzles can mean any digit other than 0. More information.