instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
wXGerDNhSNnCCedyzskswVnh, BfFNhSNnCCedybrUbI
answer:
NhSNnCCedy


question:
LudFxiaqbX, UWMPnFxiaqikiDx
answer:
Fxiaq


question:
BEDsyiimmTLGAsWrHdgjT, HjhiimmTLGAsHFIiponst
answer:

iimmTLGAs