instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
JKZiYILNeNQbJyznES, PHKILNeNQbJylltYH
answer:
ILNeNQbJy


question:
fWJdaAfOCfejXZvidHM, gOpfOCfejXZbtLvSLZI
answer:
fOCfejXZ


question:
WIGBHQqa, rTABHQDQ
answer:

BHQ