SuDoku is mostly played on a 9x9 grid. The objective of the game is to fill each cell in the grid with the numbers 1 to 9, such that in each row, column and 3x3 box, the digits 1 to 9 occur only once. This may sound like a really difficult thing to build a grid that complies to these rules, but the reality is that there are a galactic 6,670,903,752,021,072,936,960 such possible SuDoku grids (this is just a little bit over 6 with 21 zeros after it and in Zimbabwean Dollars, this is enough to buy you a loaf of bread).

       

A SuDoku puzzle is such a partially filled grid. The digits given to you are clues from which you can deduce the missing cell values.