instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
NTINFnRckGsfLqhSoA, UUONcKKFnRckGsfLqVak
answer:
FnRckGsfLq


question:
cKsJcqYvZO, UrsJcqBC
answer:
sJcq


question:
HJetceejJkjxeMNgJOGcm, wQDBqWDtceejJkjxqjplmMNzM
answer:

tceejJkjx