Logic Masters Deutschland e.V.

Standard Sudoku rules apply.
The pair of cells immediately above and below 9s sum to 9.
(Rows 1 and 9 are considered adjacent for this purpose.)
(e.g. The 2 red cells add to 9. The 2 green cells add to 9.)
The pair of cells immediately to the left and right of 9s sum to 9.
(Columns 1 and 9 are considered adjacent for this purpose.)
(e.g. The 2 blue cells add to 9. The 2 purple cells add to 9.)
The arrow outside the grid points along a diagonal. The sum of all the digits on that diagonal is either 36 or 45.
There are 2 additional, currently unlabeled diagonals of interest.
All nine 9s are along these 3 diagonals. The sums along those 3 diagonals are 36, 36, and 45.
The number 36 appears twice inside the grid in the final solution.
(Horizontally adjacent cells with a 3 to the left of a 6.)

Try To the 9s here:
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