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

Q: JXnHYuZvAYK, zhUYuZvASGhd

A: YuZvA
****
Q: XHqQIPw, brqQIkAt

A: qQI
****
Q: WjkpSSRXxNpwX, ZzxZpSSRXxcVDNYx

A:
pSSRXx
****