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

[EX Q]: jexvmCmveGzFUimQMx, RVwOSJveGzFUimrcOwjEwe
[EX A]: veGzFUim

[EX Q]: wLLwjL, arLwXm
[EX A]: Lw

[EX Q]: vaQxIw, lQQxMW
[EX A]:
Qx