instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
LeHzcEFc, WFzcExvJ
answer:
zcE

question:
kWTQrtCaoTbXIiXDphMG, pLhxkfeDoTbXIiXDpCCzTYyZv
answer:
oTbXIiXDp

question:
NlehHGwgeMzbbifV, ZLwgeMzbbicHeyvDyP
answer:
wgeMzbbi