In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.

Q: TdvkBvVyJcSdYGGPfnyml, rIvIvVyJcSdYhtxG

A: vVyJcSdY
****
Q: BUvWkxrAvDQG, rHrkxrAkCE

A: kxrA
****
Q: YxEdDWeHFrLNxJrPCaNt, PWsYcWdeHdDWeHFrLNWJEpYbZHR

A:
dDWeHFrLN
****