instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
AeYjeKwZQillzpD, SnqviKwZQillrxuTB
answer:
KwZQill


question:
fREVIdeTcakgFnwDWTVev, IbtXImseeTcakgFnwDYsKBAlux
answer:
eTcakgFnwD


question:
VSfbVvvp, XDbVvLO
answer:

bVv