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: UIjAMFDuxDDGkfQa, VdsHuxDDGkfZHZZ

Answer: uxDDGkf


Question: lkFGXvTkKm, wwELXvTkcOnG

Answer: XvTk


Question: CZgeXWXsmrUFuyMtZ, ncNjsmrUFuyMvOVMM

Answer:
smrUFuyM