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

wCfNCfxvLRAxBstRTwMSqTn, AhwxfFNCfxvLRAxBrNtf
NCfxvLRAxB

CiElmOvTqJGVJkfSaDRzE, EjDJwMyxTvTqJGVJkfluB
vTqJGVJkf

qUoifoFWOGTrrTsYh, IPZUhWOGTrrTpaYFu

WOGTrrT