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

Q: zmbmQuyNGOe, mUMEmQuyiuS

A: mQuy
****
Q: dlzequypR, Puequqv

A: equ
****
Q: AYZgxnxuQkxEAeEzgoodPgbE, vRKVKHEQkxEAeEzgopNroz

A:
QkxEAeEzgo
****