a-a a-c aaa aac aad aan aao ac- aca acc acd acn aco ad- ada adc add adn ado an- ana anc and ann ano aoa aoc aod aon aoo c-- caa cac cad can cao cca ccc ccd ccn cco cda cdc cdd cdn cdo cn- cna cnc cnd cnn cno co- coa coc cod con coo daa dac dad dan dao dca dcc dcd dcn dco dda ddc ddd ddn ddo dna dnc dnd dnn dno doa doc dod don doo naa nac nad nan nao nca ncc ncd ncn nco nda ndc ndd ndn ndo nna nnc nnn nno no- noa noc nod non noo oaa oac oad oan oao oc- oca occ ocd ocn oco oda odc odd odn odo on- ona onc ond onn ono oo- ooa ooc ood oon ooo