Logic Masters Deutschland e.V.

Yes, four given digits!
But don't be fooled, this puzzle still packs a punch!



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Rules:

• Normal sudoku rules: Place the digits 1-9 once each in every row, column, and 3x3 box.
• Yin Yang: Shade some cells such that all shaded cells are orthogonally connected and all unshaded cells are orthogonally connected and no 2x2 area may be fully shaded or unshaded.
• Circled digits must be shaded and indicate how many shaded cells are seen orthogonally from that position, including itself. An unshaded cell blocks vision.
• All 'corridors' of shaded cells (i.e. consecutively shaded cells in an orthogonal line) are an odd number of cells in length. The centre digit of each corridor equals the arithmetic mean of all the digits in that corridor.
• The centre digit along red lines also equals the arithmetic mean of all the digits on the red line.