instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
zfUPUDeKbCMQa, BkAJFJUDeKbCMZmkFu
answer:
UDeKbCM


question:
WRfFDeZjIcpidmDxtaJcv, XMxWZjIcpidmlKga
answer:
ZjIcpidm


question:
ErnfHFvAMOJHfmFweMQyWDwKD, HVvAMOJHfmFwdzbbXfWy
answer:

vAMOJHfmFw


