instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
ZGkBNEDRAwURXnxBIOJkzTvg, HMAwURXnxBMfGbPOBf
answer:
AwURXnxB


question:
SeXNqRAbKdLuWXgb, npsIWRAbKdLuUWSbvuS
answer:
RAbKdLu


question:
vVTQDdjcd, DpQDdEN
answer:

QDd