instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
DZfOjrQffR, CXOjrQQc
answer:
OjrQ


question:
nrIHKzJCdAQzUDRBYpg, JDzJCdAQzUMMYrLcfO
answer:
zJCdAQzU


question:
nhGinCtvLartcMPhJwGRbpZNrq, iQJlFKayEartcMPhJwDRROB
answer:

artcMPhJw