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

[Q]: BUvWkxrAvDQG, rHrkxrAkCE
[A]: kxrA


[Q]: ocjsZZfSBBopDtgWUT, rWmgzsZZfSBBoGWQ
[A]: sZZfSBBo


[Q]: JNpcCHNxkGEPkM, mhdcCHNxkbqadR
[A]:
cCHNxk