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: hGyDyQYdxCCuD, BQiFOyQYdxel

Answer: yQYdx


Question: rqhQxQQDdYwemFiiwcfVx, cEQDdYwemFtwpfNJC

Answer: QDdYwemF


Question: zGlyACfxZstAvIcezoOsKV, bxscXfxZstAvIcvZrmNai

Answer:
fxZstAvIc