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

[Q]: zbSNNVc, agSNNtOQ
[A]: SNN


[Q]: koIZvrJmfKCO, TBvrtjcWIZvrJmfKRZDOE
[A]: IZvrJmfK


[Q]: ngYstIwbkBFJWUhMHF, VzIGowbkBFJWUhMMobfr
[A]:
wbkBFJWUhM