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

[EX Q]: KTAFonizDqCVvucpJWrItdw, rfFonizDqCVvYbGhb
[EX A]: FonizDqCVv

[EX Q]: uZSRkFDHsGXNMaggxUn, lTrQKKpsGXNMaggEdSrEX
[EX A]: sGXNMagg

[EX Q]: odaMETbkEyIhjvG, iLZTbkEyce
[EX A]:
TbkEy