Logic Masters Deutschland e.V.

Normal Sudoku rules apply. Each row, column and 3x3 box contains each number from 1 to 9 exactly once.

Arrow Sudoku rules apply. Digits along the arrows in the grid must sum to the digit in their circle.

Ratio Sudoku rules apply. The black dots represent a 1:2 ratio between two neighbouring cells. NOT all possible black dots are indicated; a.k.a. no negative constraint.

The grey circle is an odd digit. The grey squares are even digits.

The puzzle is also available online.