instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
kWTQrtCaoTbXIiXDphMG, pLhxkfeDoTbXIiXDpCCzTYyZv
answer:
oTbXIiXDp


question:
IJQqdzqdaGEIcdyh, izlVdzqdaGGiPYz
answer:
dzqdaG


question:
mTkpAWrVxN, dgrtakpAWrVexBS
answer:

kpAWrV