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

QlJnxO, BLJnCQ
Jn

nYoRQU, gQoRZQ
oR

AlreZAYDhEQGLeeo, FxPEyeZAYDhEQuPezVK

eZAYDhEQ