Logic Masters Deutschland e.V.

Rules:

Normal sudoku rules apply.

Negators: There is exactly one "negator" cell in each row, column, and box. Digits in a negator cell have their opposite value (e.g. 2 becomes negative 2). A digit may be negated once, more than once, or not at all.

Region Sum Line: Values on the blue line have the same sum in each box the line is in.

Skyscrapers: Values in the grid represent heights (with negators being underground). Numbers outside the grid indicate the amount of visible cells in that row/column as seen from that vantage point. (To clarify, negators are "seen" if and only if they are adjacent to the edge of the grid.)

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