instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
rlBoVyFsYqpmmQmelGBg, iKKaIyFsYqpmmWcrKn
answer:
yFsYqpmm


question:
rduIwWNGM, AJqYIwWNaCap
answer:
IwWN


question:
TzsfZjQCDIHhUVRjZnpqINacSGEF, EWwbuIHhUVRjZnpRizrOoyyQg
answer:

IHhUVRjZnp