Pure Sudoku

Sudoku is a placement puzzle, also known as Number Place in the United States. The aim of the puzzle is to enter a number from 1 through 9 in each cell of a grid,most frequently a 9×9 grid made up of 3×3 'regions', starting with various numbers given in some cells (the 'givens'). Each row, column and region must contain only one instance of each number. Completing the puzzle requires patience and modest logical ability. Its classic grid layout is reminiscent of other newspaper puzzles like crosswords and chess problems. First published in the United States, Sudoku initially became popular in Japan in 1986 and attained international popularity in 2005. Now you can play SuDoku on your PC, forget about pen and paper.