Logic Masters Deutschland e.V.

Normal Sudoku rules apply

Little Killer Sudoku rules apply. Digits outside the grid are the sum of the diagonal pointed at.

A red dot is placed in a 4-cell square if the diagonally opposing digits in the square have the same sum.
For instance:

46
79

7+6 and 4+9 both add to 13

A blue dot is placed in a 4-cell square if the diagonally opposing digits in the square have the same difference.
For instance:

72
36

7/6 and 2/3 both have a difference of 1

There is a negative constraint on both red and blue dots. (All possible dots are given)

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