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

Answer: MPTh


Question: QzJdafaGRLWEguLkOaw, brmPLBoaGRLWEguEaF

Answer: aGRLWEgu


Question: DAqQWBjjLkPgwIytMsu, JWGlkXZjLkPgwIqU

Answer:
jLkPgwI