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

[Q]: mCxQTIaXN, mWQTIaxzPT
[A]: QTIa


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


[Q]: imNFQCeBWsYFgITD, FxeBWsYFKCm
[A]:
eBWsYF