instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
XEvxzelZaWRO, zXIelZaWBUn
answer:
elZaW


question:
GoodBOwvrki, kRCsdBOwvrakgiH
answer:
dBOwvr


question:
uGGjWPaTodDpCZOIHiq, JgodDpCZOIKHYsAPH
answer:

odDpCZOI