instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
uqazNuZhdJhw, KbnrzNuZhBdp
answer:
zNuZh


question:
YHLJZrFQ, aSLJZQuo
answer:
LJZ


question:
wmzcNyMQ, XMEcNyHKB
answer:

cNy