In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
--------
Question: eeoJEtGHPDvHck, ezPGHPDvHSf

Answer: GHPDvH


Question: lrBJDRkT, jmBJDrI

Answer: BJD


Question: aPpLMnIyhdatDcoz, ViqmSPNgMnIyhdatDcNHUAYfPE

Answer:
MnIyhdatDc