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

[Q]: biAihydBoNlzR, IAloNhydBolwUz
[A]: hydBo


[Q]: jLbHvZmecfxMcGLXGVsO, erFBGmecfxMcJtDyKGZ
[A]: mecfxMc


[Q]: VsRhthUwj, JZLnhthUWLo
[A]:
hthU