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

[EX Q]: zqwhMdAdXQfQCAmVNaYZm, toYMIwQeadAdXQfQCAmLyheFOv
[EX A]: dAdXQfQCAm

[EX Q]: VRXUhOYfTul, JqZUhOYKq
[EX A]: UhOY

[EX Q]: ZAluuFAOxwljeXFAH, HrpUuFAOxwlUkpZR
[EX A]:
uFAOxwl