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

[Q]: QqtCFzXHPNFXx, XECFzXHPSGwUuk
[A]: CFzXHP


[Q]: cZSEmdgP, YsSEmEIM
[A]: SEm


[Q]: JZpxZwsL, BhpxZgyP
[A]:
pxZ