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

[Q]: dsngGP, KvnglB
[A]: ng


[Q]: gXwuhXJrEdzGOmLSKdK, TohXJrEdzGavU
[A]: hXJrEdzG


[Q]: AXsQiFtFDC, yAQiFtcLn
[A]:
QiFt