instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
aeQjEeiWGONmzGimhGiw, RIEeiWGONmOZuVYr
answer:
EeiWGONm


question:
ZyrpGdXvvtrKQIxU, CLNGdXvvtrKQDpicfqLdt
answer:
GdXvvtrKQ


question:
fsZzICvgTsqijYJylscIn, bPCvgTsqijZY
answer:

CvgTsqij