instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
UysTOtIRtRorNAFKKYD, icDOtIRtRoropYVaKzJ
answer:
OtIRtRor


question:
AxRSlkQfWHrdlgQG, iXIOrmlkQfWHTy
answer:
lkQfWH


question:
fHCPzsdj, DGxPzsWVM
answer:

Pzs