Logic Masters Deutschland e.V.

Flash back to middle school where this "S" was drawn on notebooks and lockers everywhere.

• Normal Sudoku rules apply.
• Zipper Lines: Digits equidistant from the center of a colored line must sum to the number at the center of that line. (Differently colored lines indicate that each is treated as a separate Zipper Line.)
• Unique Sums: Components of Zipper sums are unique across all Zipper Lines. (For example: The zipper line "2 7 5" would prevent "2 1 7 6 5" from being valid because "2 + 5 = 7" is already used.)

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