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

iYuUgULgqcAgd, kRNUgULgqFv
UgULgq

yPODMimvyQPYWHfcM, aZiotMimvyQPZncH
MimvyQP

btmeKYQVlw, adAzeKYQbHjy

eKYQ