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: KJswoapnXz, EQswoaFyH

Answer: swoa


Question: JIOKyo, oPOKsX

Answer: OK


Question: kXlhGzzIpnpANEk, tsOnGzzIpnpFdoGxAr

Answer:
GzzIpnp