instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
xMxyohPBlJIEBqghiMdBQPwq, xsBlJIEBqghlMosK
answer:
BlJIEBqgh


question:
hGyDyQYdxCCuD, BQiFOyQYdxel
answer:
yQYdx


question:
uCrCWfvKB, IPLqrCWfEVe
answer:

rCWf