instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
yhhzISsXKEbA, KlPrazISsXKzmrVBG
answer:
zISsXK

question:
AedXEOrEgvnzF, TVTEOrEgvxKuJgv
answer:
EOrEgv

question:
YxEdDWeHFrLNxJrPCaNt, PWsYcWdeHdDWeHFrLNWJEpYbZHR
answer:
dDWeHFrLN