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: VRXUhOYfTul, JqZUhOYKq

Answer: UhOY


Question: HHJAHyvNCGmJEljWrjvHOqf, msPVEbNCGmJEljsKRX

Answer: NCGmJElj


Question: pQcXkOS, wRcXkhYC

Answer:
cXk