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

Q: zeuyZKwvIOfx, BlmZKwvspUt

A: ZKwv
****
Q: PGjDRPDzGaBR, rpIJRPDzWi

A: RPDz
****
Q: tZCyEpuaL, tsyEpqQv

A:
yEp
****