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

Q: ZRjPgqbLL, uIsmPgqbBB

A: Pgqb
****
Q: KJswoapnXz, EQswoaFyH

A: swoa
****
Q: XAktEBIccGIO, PPvpNtEBIccjEG

A:
tEBIcc
****