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

SODsrWUjUBSgA, WIWUjUBCUUs
WUjUB

zeuyZKwvIOfx, BlmZKwvspUt
ZKwv

saQbkcMMJLbV, qQzkcMMJNwuzD

kcMMJ