instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
OrcQOvMBhmwP, mnWrzcQOvMBnLwI
answer:
cQOvMB


question:
zBxuZfJgYrlRSzkmAktO, YNMgYrlRSzklmBOH
answer:
gYrlRSzk


question:
CWVjfKaprOcHrRAzRRGC, dEbWBiKaprOcHrWrBvnBH
answer:

KaprOcHr