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

Q: zfUPUDeKbCMQa, BkAJFJUDeKbCMZmkFu

A: UDeKbCM
****
Q: ATmVEtUuZOgsBUuL, UMUuZOgsBPVT

A: UuZOgsB
****
Q: YaQbSDSTCNbdC, UJUQEQbSDSTeA

A:
QbSDST
****