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

HiEuutntEBpU, fdkqEuutntEBABdGZRND
EuutntEB

FiKGCRXutEOzMqP, xdxRXutEsl
RXutE

HgPVqDTCZO, fpmcqDTCLRWQ

qDTC