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

[Q]: yiKkIxbKvNk, znaIxbKggg
[A]: IxbK


[Q]: DUhUbmfLuOFAQann, kwnzfLuOFAErR
[A]: fLuOFA


[Q]: fCEMaFSPKYZfoGMtvoFquo, PlMsAZfoGMtvoFqmYx
[A]:
ZfoGMtvoFq