The grid is composed of 81 squares and divided into nine blocks, each containing nine squares. The goal: each of the nine blocks has to contain all of the numbers 1 to 9 within its squares; each number can appear only once in a row, column or box. In addition, each vertical nine-square column as well as each horizontal nine-square line across within the larger square must also contain the numbers 1 to 9 without repetition or omission. There is only one correct value for (e)(m).