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

[Q]: rvLoiycpZw, idcvoiycpcLyD
[A]: oiycp


[Q]: jeQzwP, kSQzxq
[A]: Qz


[Q]: YxhqfBlOdFFTOCaY, cmqfBlOdFFmOvJOf
[A]:
qfBlOdFF