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: JXnHYuZvAYK, zhUYuZvASGhd

Answer: YuZvA


Question: QKlzsmHyBcC, snPtzsmHdMIv

Answer: zsmH


Question: expMYEQFnXiDbHDTc, dEGrlQFnXiDbERBIqs

Answer:
QFnXiDb