instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
uGDJixAmSiVaFRmfKRM, NsTGxsJixAmSiVageSw
answer:
JixAmSiVa


question:
RwqzMTeLMdPx, qaWtYhqzMTeLMdHbWDT
answer:
qzMTeLMd


question:
yfMAcR, AaMAjR
answer:

MA