the test cases didn't fail, the codewars test checker didn't see True values being returned 😅

That's not a bug... it's a feature for... COMPLIMENTING INTERNET HANDLES!

return f"Hello {n}, you are very cool!"

If I input "@" it works :D

I think you can probably remove the "a in arr and b in arr" part, because the instructions said it was guarenteed that a and b would be in the list. Just a tip.

literally just said: "I DO NOT NEED TO EVEN DEFINE A FUNCTION"

haha gauss' method go BRRR
who needs for loops