Sudoku is a logic based number placement puzzle. The objective is to fill in the 9x9 grid so that each column, each row, and each of the nine 3x3 boxes (or regions) contains the digits from 1 to 9 only one time each. Starting with a partially completed grid, your objective is to find the one solution that correctly solves the puzzle. Every sudoku puzzle
has one and only solution, and can be solved through logic alone.