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

[EX Q]: ilgSzrcUKLTNLJbMKMKSt, hFXIuUKLTNLJbMKWxSCkDjY
[EX A]: UKLTNLJbMK

[EX Q]: iMwanJBuMdiZDL, kIafHeBuMdiZmKNA
[EX A]: BuMdiZ

[EX Q]: WbQJmMaf, bWQJmwB
[EX A]:
QJm