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

[Q]: trHTzJpm, aCHTzVVA
[A]: HTz


[Q]: HKqfdEvqDuGhWByFlzIEeYh, VVaZfkLCMuGhWByFlzIOZaXbMCA
[A]: uGhWByFlzI


[Q]: YlKurYp, RKQKurrc
[A]:
Kur


