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

[Q]: PIcbiJj, hedcbiZHF
[A]: cbi


[Q]: RNYHvcNnbsUdJLvS, PpNnbsUdglWhl
[A]: NnbsUd


[Q]: BPzEusYlZnk, EgoDzEusYFlaPG
[A]:
zEusY