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

[Q]: gfDDsblwUryUw, UWaRisblwUTqTM
[A]: sblwU


[Q]: vSFxjd, AHFxpi
[A]: Fx


[Q]: ZJxAVXnecTYJbaldmPqEMLzbi, cwecTYJbaldpSCRfbmG
[A]:
ecTYJbald