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

[Q]: DGvUCrUVlUnQBShkWnfnceGasvI, NfzGUnQBShkWnpLMnY
[A]: UnQBShkWn


[Q]: ZRjPgqbLL, uIsmPgqbBB
[A]: Pgqb


[Q]: QXTaCmAUAZfBvTYKCrB, ufqLYWRAZfBvTYKhK
[A]:
AZfBvTYK