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

[Q]: skZGHS, HsZGge
[A]: ZG


[Q]: ljwjMioOwfOltGBaE, TneNGsoOwfOlxnWWW
[A]: oOwfOl


[Q]: MJdhtDWpbmEpjMD, rePRWOtDWpbmEpjCSm
[A]:
tDWpbmEpj