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

[Q]: BeEgLISxThm, UGLISxEtP
[A]: LISx

[Q]: IJQqdzqdaGEIcdyh, izlVdzqdaGGiPYz
[A]: dzqdaG

[Q]: peWIPNiJqORiWAAqNknR, cidztPNiJqORiWCuR
[A]:
PNiJqORiW