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

[Q]: YCAyruPTTHWhCYaiXfIl, OETdzqAyruPTTHWgS
[A]: AyruPTTHW


[Q]: CuizrSvJTRWZK, udyrSvJTRZzkS
[A]: rSvJTR


[Q]: ARGchkRez, kUwchkZPE
[A]:
chk