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: gfXPLNzsyfEotmHL, oJeXPLNzsyJuXP

Answer: XPLNzsy


Question: YlhtTQgHiffTbIbBrcHMqFKCdWz, HyregFgMffTbIbBrcHYUnnQvGlx

Answer: ffTbIbBrcH


Question: tAhWdyRqV, DNuWdylIE

Answer:
Wdy