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: ilgSzrcUKLTNLJbMKMKSt, hFXIuUKLTNLJbMKWxSCkDjY

Answer: UKLTNLJbMK


Question: vSFxjd, AHFxpi

Answer: Fx


Question: dkJxiAGBSiqsTsrzv, WdtzxxQyJxiAGBSiqpv

Answer:
JxiAGBSiq