Wilson's Theorem

[JellyFish]

We touched on Wilson's Theorem [(p-1)! = -1 (mod p)] in class but didn't do any examples so I am struggling to find 18!(mod 23).

Thank you for the help.

 

[daon]

\(\displaystyle 18!(19)(20)(21)(22) = (22)! \equiv -1_{\% 23}\)