In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.

Q: SQNzngllNbOkKDK, MijfNzngllNDfWge

A: NzngllN
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Q: CkZOSZevST, bbZOSZIg

A: ZOSZ
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Q: mKSsSZBwVdsydNFM, ASxosUHwVdsydNpzBxim

A:
wVdsydN
****