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

[Q]: oiNEYHxbvAb, bcDDdEYHxbCREd
[A]: EYHxb


[Q]: AuSFmN, crSFXM
[A]: SF


[Q]: zIEnRbuUrAXnKvz, uwEQGHRbuUrAXQrBLQw
[A]:
RbuUrAX