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

YPeBvuJXaSLLPhKpUQ, ryjPdyuJXaSLLPhIzBeJP
uJXaSLLPh

yKtQOhYvrJVH, HQsTQOhYvPP
QOhYv

ixYAEQQlCkU, tUbgEQQlMs

EQQl