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

[Q]: PIcbiJj, hedcbiZHF
[A]: cbi


[Q]: edjRAatlaiCmWkpqMh, qDZYVWCDTRAatlaiCmYH
[A]: RAatlaiCm


[Q]: UnDMEwrfHoQ, lbkExEwrfHGl
[A]:
EwrfH