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

Q: KJswoapnXz, EQswoaFyH

A: swoa
****
Q: CwTYJWQbzEZkvcqKn, hBnhJWQbzEZkKmVM

A: JWQbzEZk
****
Q: SMfzGIXcY, PUIzGIsu

A:
zGI
****