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

Q: lkFGXvTkKm, wwELXvTkcOnG

A: XvTk
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Q: KfjqnJLciTXqkJK, yqfRcfqnJLcisSB

A: qnJLci
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Q: dymUAWcNOUarORGH, QemAWcNOUakqTJM

A:
AWcNOUa
****