Normal sudoku rules apply. All cages are minmax killer cages. Digits in a minmax killer cage do not repeat. The clue in the top left indicates the sum of the smallest and the largest digit that are contained in the cage. For example, a cage containing the digits 1, 3, 6 and 8 would have the minmax killer clue 9=1+8. On the main diagonals digits do not repeat.