Normal rules for a 6x6 irregular sudoku apply: each row, each column and each bold-outlined region contains the digits 1 to 6 exactly once.
Normal Kropki rules apply (no negative constraint): digits separated by a white dot are consecutive. Digits separated by a black dot are in a 2:1 ratio, i.e. one of the two digits is double the other. Not all dots are given.
Solution code: The bottom row, read from 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.