instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
PShMbsbexXGlpBuMMDZZS, sVqGxSexXGlpBxuHXoI
answer:
exXGlpB


question:
oUEcuLINTDdvdOne, thzWccuLINTDQfNZwH
answer:
cuLINTD


question:
LkVrlH, lsVruR
answer:

Vr