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

Q: yhhzISsXKEbA, KlPrazISsXKzmrVBG

A: zISsXK
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Q: vMYfFo, EHYfnP

A: Yf
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Q: MLiJxOmUOkqLZXFOXHznq, GdmCOhKYrJxOmUOkqLdGDTZ

A:
JxOmUOkqL
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