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

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


[Q]: NUuLSmDjCKcJPc, lGGSLIDjCKcJBo
[A]: DjCKcJ


[Q]: oqRDypMdJENLN, XarxCLDypMdJmNiG
[A]:
DypMdJ