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

jXqEDHTCxTiUAICWZJdpmYq, GBTCxTiUAICZKnLgZBXi
TCxTiUAIC

cjDuPZOHjystHnF, okWVdUDuPZOHjSCaEecP
DuPZOHj

LZSDIUAyHpgs, pEIUAyHap

IUAyH