Normal Sudoku rules apply. In cages, digits must sum to the small number in the top left corner of the cage (if given). Digits in cages may not repeat. IN ALL CASES where two orthogonally adjacent digits sum to A or B, a dot is shown between them: ie White dot = Sum is always A; Black dot=Sum is always B; and Grey dot=Sum is A or B. A and B are different, and finding their values is part of the puzzle.