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

[EX Q]: PnRypl, HvRydi
[EX A]: Ry

[EX Q]: aIZIsqL, wxSZIsEnO
[EX A]: ZIs

[EX Q]: MkHhFTLo, GEWHhFam
[EX A]:
HhF