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

xtCJGe, DXCJSw
CJ

sHndIbPaygfNvnquxIHeteW, huLmJWXZIgfNvnquxIViQDhbuoL
gfNvnquxI

UoTdRogEAUSKQ, DFXtRRogEAUSRaZtIn

RogEAUS