Logic Masters Deutschland e.V.

Normal sudoku rules apply.

Digits must not repeat along the marked diagonal.

The solver must find a single non-branching loop of orthogonally connected cells which enters every 3x3 box but does not touch itself orthogonally. The shape of the loop is perfectly symmetrical across the marked diagonal and adjacent digits on the loop must differ by at least 4.

A digit in a circle or square must show the number of loop cells in the surrounding 9 cells (including itself if it is on the loop). Circles contain odd digits. Squares contain even digits.

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