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

Q: nXVXIEGP, fkXIEkU

A: XIE
****
Q: nxoXDohHr, WcbkXDohFbJ

A: XDoh
****
Q: OQSgJdXvFcnZWBfZJYCbpciK, exjDMunEdnZWBfZJYCbFXau

A:
nZWBfZJYCb
****