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

[EX Q]: JjEQVKijeyEQ, dwSVKijeywCTvb
[EX A]: VKijey

[EX Q]: uGDJixAmSiVaFRmfKRM, NsTGxsJixAmSiVageSw
[EX A]: JixAmSiVa

[EX Q]: IieWyRrlgIMgwCJ, FyYaarlgIMgUBu
[EX A]:
rlgIMg