Logic Masters Deutschland e.V.

Normal Sudoku rules apply (each row, column, and given 3x3 box must contain the digits 1 to 9). Cells with a shaded circle are odd digits; cells with a square are even. And everything is mod 10. So a 6 might mean 6, or 16, or 26, etc.

The following variants are all subject to the mod 10 rule. Digits in a cage must add to the sum in the top left corner - e.g. if the number in the corner is 0, the digits might sum to 10, 20, 30, etc. Digits on either side of a black dot must have a ratio of 1:2 (one is double the other) - 6 can be paired with 2 (6x2=12), 3 (3x2=6), or 8 (8x2=16). Digits on either side of an X must sum to 10 and digits on either side of a V must sum to 5 (or 15).

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