1-10 CACCB ABABA11-20 BBABC BABCA
21-30 CBBAA ACCAB31-40 CBCCC BACCB
41-50 BCCAB AACCC51-60 BACBC CACBB(https://www.daowen.com)
61-70 AAAAB ACACC71-75 ABBCC
