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

Q: yiKkIxbKvNk, znaIxbKggg

A: IxbK
****
Q: dlzequypR, Puequqv

A: equ
****
Q: FgQsxN, UMQsIa

A:
Qs
****