instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
iupYjFXrrMqWzJSLUSwmEukHc, hqajjWrrMqWzJSLnF
answer:
rrMqWzJSL


question:
IJQqdzqdaGEIcdyh, izlVdzqdaGGiPYz
answer:
dzqdaG


question:
HkZWzmnA, EkVZWzxkP
answer:

ZWz