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: PQSFjlnU, kTSFjMUh

Answer: SFj


Question: OezHeoe, ouUzHemU

Answer: zHe


Question: TPVDEUjDgAQZRyeygymPVv, FTAGEQZRyeygymPhPKAG

Answer:
QZRyeygymP