Logic Masters Deutschland e.V.

This is a Japanese Sums puzzle with digits from 1 to 9 with additional rules.

Rules for Japanese Sums: In the diagram, some fields are to be blackened. In the remaining fields, digits from 1 to 9 must be entered in such a way that no digit is repeated in any row or column. The hints at the outside the diagram indicate the sums of connected digits (with no black field in between) in the correct order.

Additional rules: If there is a 20 in a field of the diagram, this field itself is normal, but the 4 orthogonally adjacent fields form wild 20s. I.e. the sum of the digits of these 4 fields is 20; black fields count as 0.

Furthermore, the fields above and below the 20 are invisible in the row in which they are located; i.e. they are completely ignored when the sums are calculated. Likewise, the fields to the left and right of the 20 in the column in which they are located are invisible and are ignored when the sums are calculated. This applies regardless of whether the ignored field contains a number or a black field. The optical marking is to emphasize these special features and has otherwise no meaning.

Also in rows or columns with wild 20s, digits must not be repeated.