The grid is composed of 81 squares, which is divided into nine blocks, each containing nine squares. The goal: each of the nine blocks has to contain all of the numbers 19 within its squares; each number can appear only once in a row, column or box. In addition, each vertical ninesquare column, or horizontal ninesquare line across, within the larger square, must also contain the numbers 19 without repetition or omission. There is only one correct solution to the puzzle.
