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

[Q]: tGBRASi, QABRAtL
[A]: BRA


[Q]: trHTzJpm, aCHTzVVA
[A]: HTz


[Q]: dxYLFgnuRtACG, btFgnuRNeApY
[A]:
FgnuR