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

slTUxy, oqTUYa
TU

yiKkIxbKvNk, znaIxbKggg
IxbK

HerJMBMurOVxdWFZjZDdk, nNoBJoqMBMurOVxdWIsAqoX

MBMurOVxdW