instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
elloYaejTczBiiNOU, XoCPzloYaejTcXYtKODL
answer:
loYaejTc


question:
AkYuNemHGBEDF, uluNemHGAycbWX
answer:
uNemHG


question:
XslfdGbNhpqFcWTBLo, uHuOxdGbNhpqxLPUjr
answer:

dGbNhpq