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

[EX Q]: DwkTGsIXLfmjMV, VqRlMxtsSBkTGsIXLfmjbvI
[EX A]: kTGsIXLfmj

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

[EX Q]: JLilLqqzGtWT, ebNlLqqzGtfM
[EX A]:
lLqqzGt

