Normal sudoku rules apply. Normal killer sudoku rules apply ie digits may not repeat within a cage. Normal little killer sudoku rules apply ie each arrow denotes the sum of the digits along that diagonal (and digits may repeat along the diagonal). In this puzzle, each killer/little killer sum is equal to one of two numbers M or N (both of which need to be deduced). For example, the two sums could be 8 and 17; and therefore each cage and arrow sums to either 8 or 17.