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

[Q]: WjyKtxKtEYjP, vuBZJZyKtxKtXRZs
[A]: yKtxKt


[Q]: XEvxzelZaWRO, zXIelZaWBUn
[A]: elZaW


[Q]: HcnFDKSqXtXuNUUVB, rTvneJxgtoKSqXtXuNUUScXy
[A]:
KSqXtXuNUU