instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
vFuggVITQuctFG, hdCIWWuuggVITQwr
answer:
uggVITQ


question:
TTagIJmzrOTdnKr, UONmtdHJmzrOTduWo
answer:
JmzrOTd


question:
SoAWYrhVlEugzfKVrq, tFcqUVlEugzfnE
answer:

VlEugzf