Standard sudoku: each digit 1-9 appears exactly once in each row, column, and 3x3 region.
Killer: in cages, digits do not repeat and sum to the number in the top left corner.
German Whisper: Digits connected by a green line must have a difference of at least 5.
Solution code: Row 9, Left to Right.
Please note: The German version of this page has changed. It is possible that this page does not contain the latest information.