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

Q: xzMUdHcoYJFWLOILjrg, vCscoYJFWLzO

A: coYJFWL
****
Q: SFQHJlK, dHfQHJoUC

A: QHJ
****
Q: yHUIpfKiGde, AEDpfKixbT

A:
pfKi
****