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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.