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

[EX Q]: SUueHhzGsanfsalEEc, KygEhzGsanfsapbKKX
[EX A]: hzGsanfsa

[EX Q]: jXbgnl, lUbglP
[EX A]: bg

[EX Q]: bSBuJiZniSlZtO, AcuJiZniSRAOAv
[EX A]:
uJiZniS