Logic Masters Deutschland e.V.

Clues outside the grid give the sums of the digits that are orthogonally adjacent to either the 1 or 9 in the row or column. The solver must determine which clues are for ones, and which are for nines. Where two clues appear, they give the sums for both the 1 and 9, and the order in which the sums appear (left to right in a row, top to bottom in a column). Some clues are replaced with question marks, which represent unknown numbers. Equality and inequality signs give the relationship between the two clues.

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