Logic Masters Deutschland e.V.

Normal sudoku rules apply:

159: Digits in column 1 indicate the column in which the digit 1 appears in that row (e.g. if r4c1 is a 6, r4c6 is a 1). The same applies to columns 5 and 9, with the digits 5 and 9 respectively.

Quadruples: Digits in circles must appear in the surrounding 2x2 cells.

Have fun, leave a comment if you enjoy the puzzle!

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