MainpageFractalsBirthprimesWordBabygenTexturizeProgramsPhonewordData MatrixMap
SudokuSudokutoWordokuCodokuSudoku3DSudokuGTKakuroFillominoHitoriArukone
HashiShuffleBogglemPuzzleCalcuDokuSangerProbabilityLærerShowcase

Quad Middle(QM)

If you have three black in the middle, the last must be white