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: iUtNuU, iKtNWk

Answer: tN


Question: NUuLSmDjCKcJPc, lGGSLIDjCKcJBo

Answer: DjCKcJ


Question: ImlKphCUkTpVBbera, vXzahCUkTpTa

Answer:
hCUkTp