instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
fWJdaAfOCfejXZvidHM, gOpfOCfejXZbtLvSLZI
answer:
fOCfejXZ


question:
JzbEpAquDJFKcNvEWZxVqRV, PFiJlpAquDJFKcNcqOpMeAv
answer:
pAquDJFKcN


question:
kIBDjQLEZepVNHqnKqhine, hTZepVNHqnYTajyzv
answer:

ZepVNHqn