search – Karp-Rabin – what is the entry for the complexity of the worst case scenario?

I'm trying to determine the entry for the worst case of Karb-Rabin complexity, regardless of the hash function used. However, I am seeing these two answers on the internet:

• Chain "AAAAAAAA" and pattern "AAA"
• Chain "AAAAAAAB" and pattern "AAB"

Which of these entries would have the worst execution time in Karp-Rabin? Thank you!