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

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


[Q]: MvALRGKkpALcKdhTtnm, neMkRGKkpALcKdcaxnXEPxW
[A]: RGKkpALcKd


[Q]: PwWjvP, uPWjXK
[A]:
Wj