Normal sudoku rules apply. Digits in cages do not repeat, and sum to the small clue, if given. Grey circles contain 1 or 9. One grey loop is Entropic, one is German Whisper, and one is Region Sum; the solver must determine which is which. Entropic: every 3 cells along the line contain one low digit {123}, one middly digit {456}, and one high digit {789}. German Whisper: adjacent cells along the line differ by at least 5. Region Sum: box borders divide the line into segments with the same sum.