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

[Q]: AeYjeKwZQillzpD, SnqviKwZQillrxuTB
[A]: KwZQill


[Q]: tmBlKUto, eFDBlKLy
[A]: BlK


[Q]: KddcTMQNDggQK, EaKmTMQNDHdoeL
[A]:
TMQND