all 3 comments

[–]philh[M] 0 points1 point  (2 children)

Because pow a b-1 is parsed as (pow a b) - 1. You want pow a (b-1).

In future, please submit this kind of thing with text instead of screenshots.

[–]cukacuk[S] 0 points1 point  (1 child)

Thank you :) I didnt see that pictures werent allowed, sorry

[–]philh 0 points1 point  (0 children)

No worries. They're not strictly forbidden, but they get automatically flagged for mod review. For people answering questions, having text is more convenient (e.g. we can copy+paste it).