instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
yPODMimvyQPYWHfcM, aZiotMimvyQPZncH
answer:
MimvyQP


question:
oXZmCSdFrMumlZcP, eFpOZmCSdFrIuHeS
answer:
ZmCSdFr


question:
QOrRQEOLIgxygC, eyYRQEOLIgWGoe
answer:

RQEOLIg