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

[Q]: yQCDWefwvrPP, RwoMDWefwhSxTR
[A]: DWefw


[Q]: KvPFobZEGs, eKFobZEtnm
[A]: FobZE


[Q]: tAbkSArSmqOEow, MkiVlXbkSArSpuWMM
[A]:
bkSArS