instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
AedXEOrEgvnzF, TVTEOrEgvxKuJgv
answer:
EOrEgv


question:
srPyjmTQhdFFMcQ, QQGBdtyjmTQhmfEy
answer:
yjmTQh


question:
hrhDNwfJv, MfSChDNwfmBnur
answer:

hDNwf