Normal sudoku rules apply.
Mod-5 Counters: Circled digits indicate how many of the up to 9 cells surrounding the circle (including itself) have the same value modulo 5 as itself. E.g., a circled 2 would count how many of the surrounding digits are from the set {2, 7}. Not all such circles are necessarily given.
Example for reference:
Solution code: Row 4
on 5. July 2024, 00:41 by nicky1306
What an enjoyable solve! Thank you!
on 1. July 2024, 08:47 by bradd
Gorgeous puzzle, thank you! :)
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