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: ChKUlYUTQQBjZMZkgEed, lmQQBjZMZkgdEf

Answer: QQBjZMZkg


Question: jAinxmaQUrmu, jqeEnxmaQUrWlrEqW

Answer: nxmaQUr


Question: OGgyJRkc, qfMyJRPo

Answer:
yJR