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

[EX Q]: sRTQgRgRUjEooapKdR, vzsBgRUjEooLBkYeH
[EX A]: gRUjEoo

[EX Q]: rvLoiycpZw, idcvoiycpcLyD
[EX A]: oiycp

[EX Q]: rkoFvjCysqarjeUSmim, ZKIfJHtRjCysqarjQmm
[EX A]:
jCysqarj

