instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
TWVTGNBh, nEVTGWq
answer:
VTG


question:
HaIPcFXLhYDp, AdIPcFXtJdRE
answer:
IPcFX


question:
tLXYlaMzYJhuCsHssoL, YRbULioLlaMzYJhugtAtaAMs
answer:

laMzYJhu


