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: jFVaEHbMrrkW, ekfVaEHbPnBnM

Answer: VaEHb

Question: RtOkkgLvhgfGlX, vCOkgLvhzOa

Answer: kgLvh

Question: LdGFfgKQPOwefYePPdDqHg, WdMxKQPOwefYwxBV

Answer:
KQPOwefY