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

[Q]: YPeBvuJXaSLLPhKpUQ, ryjPdyuJXaSLLPhIzBeJP
[A]: uJXaSLLPh


[Q]: cvZfWOwa, xOfWOhZs
[A]: fWO


[Q]: KFKkZv, eQKkIn
[A]:
Kk