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

Q: eJPZzg, lFPZbI

A: PZ
****
Q: PIcbiJj, hedcbiZHF

A: cbi
****
Q: waCTyqXEzwkUinyhoyTDb, DhyjgqXEzwkUinFg

A:
qXEzwkUin
****