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

[Q]: dsngGP, KvnglB
[A]: ng


[Q]: EJZYVxgFxPoOSDlLfK, uTLTIETHZYVxgFxPoPwr
[A]: ZYVxgFxPo


[Q]: hLBPfk, kiBPdR
[A]:
BP