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

[EX Q]: iJbjApY, ggwbjAws
[EX A]: bjA

[EX Q]: ktABEFESAVHZkkY, uMjxiESAVHZkZgWUte
[EX A]: ESAVHZk

[EX Q]: DLxENBCyqIqbkPom, nGxinhNBCyqICT
[EX A]:
NBCyqI