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

[Q]: sbQJFbUtmnKaEJePFPeRM, QzfvkdZbUtmnKaEJNrWD
[A]: bUtmnKaEJ


[Q]: CzkPtkpMTDeNZwCPbJJn, HzpMVDeNZwCPbJVOU
[A]: DeNZwCPbJ


[Q]: uhmVYfoqu, BgVYfoMZwD
[A]:
VYfo