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

[Q]: Owbiay, exbime
[A]: bi


[Q]: XmiLktrUjJDOCJ, UIKrUjJDOQsR
[A]: rUjJDO


[Q]: JWtaRdFlfW, aFRdFlTW
[A]:
RdFl