instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
wXGerDNhSNnCCedyzskswVnh, BfFNhSNnCCedybrUbI
answer:
NhSNnCCedy


question:
cCDTMXjGMNikONun, jpcMXjGMNizBEWQzT
answer:
MXjGMNi


question:
sjcJOlCisVXegBltYdSTkggcfL, QvxZXiVXegBltYdSKdGwEeE
answer:

VXegBltYdS