instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
BICndZkjoSidWivWATvtqsS, FzVWjoSidWivFaQhkRT
answer:
joSidWiv


question:
CuizrSvJTRWZK, udyrSvJTRZzkS
answer:
rSvJTR


question:
UBuOXZQFQsyMEpo, nBSpyOXZQFQsCq
answer:

OXZQFQs