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

[Q]: oCtWZYdkvZ, pkktWZYdEHMW
[A]: tWZYd


[Q]: GrvtMjEvRlmN, ifGOWMjEvRPSOZK
[A]: MjEvR


[Q]: icttRQiCLMV, pSzKRQiCnu
[A]:
RQiC