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

HiEuutntEBpU, fdkqEuutntEBABdGZRND
EuutntEB

XmiLktrUjJDOCJ, UIKrUjJDOQsR
rUjJDO

BUfWpfiQuMhVwOInDNre, bdEkupEtZiQuMhVwOIhuVQ

iQuMhVwOI