Sudoku Puzzle is a grid with 8 squares deep and 8 squares wide. In each square you need to enter numbers from 1 to 8. The meaning of the puzzle: use the number in each row, column and 4x2 block only once. Also the puzzle may contain the regions of random (irregular) shape; this variant is called Jigsaw Sudoku ("Geometry Sudoku", "Geometry Number Place", "Irregular Sudoku", "Kikagaku Nanpure").