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

[Q]: yxJxNRLEnKGHziJtfb, KfReWhEnKGHzitzfPWzK
[A]: EnKGHzi


[Q]: HLtkkRnWkgIdqbQH, dWeFUtkkRnWkgIdZhlQh
[A]: tkkRnWkgId


[Q]: XexEZrtbU, RTxEZrrHYA
[A]:
xEZr