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

[EX Q]: ZhHtTXaUmsQfUMNrnt, KvvebSXaUmsQfBspwM
[EX A]: XaUmsQf

[EX Q]: AedXEOrEgvnzF, TVTEOrEgvxKuJgv
[EX A]: EOrEgv

[EX Q]: zglpAvPZPgStY, LHqPgVlpAvPZPgAJBPLLqg
[EX A]:
lpAvPZPg