Logic Masters Deutschland e.V.

Normal sudoku rules apply (place the digits 1-9 in every row, column and 3x3 box). Digits along an arrow sum to the digit in the attached circle.

In the cages, orthogonally adjacent pairs of cells may not sum to a multiple of 3. So if r2c3 contains a 2 then none of r1c3, r3c3 or r2c2 may contain a 1, 4 or 7.