instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
hCRsCCOoLMpjXwI, lVRCOoLMpxaYFbY
answer:
COoLMp


question:
aeQjEeiWGONmzGimhGiw, RIEeiWGONmOZuVYr
answer:
EeiWGONm


question:
bkxFnUbepDEMMZqlBa, tJqGnUbepDEkD
answer:

nUbepDE