instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
uZSRkFDHsGXNMaggxUn, lTrQKKpsGXNMaggEdSrEX
answer:
sGXNMagg


question:
nxTtNYaazlOyEBApiUSJS, BLazlOyEBCV
answer:
azlOyEB


question:
HcsJGsgNgMZBgKCOyMt, TbwsJGsgNgMZiciNBAQkN
answer:

sJGsgNgMZ