a-a a-c aaa aac aad aaf aan aao ac- aca acc acd acf acn aco ad- ada adc add adf adn ado af- afa afc afd aff afn afo an- ana anc and anf ann ano aoa aoc aod aof aon aoo c-- caa cac cad caf can cao cca ccc ccd ccf ccn cco cda cdc cdd cdf cdn cdo cfa cfc cfd cff cfn cfo cn- cna cnc cnd cnf cnn cno co- coa coc cod cof con coo daa dac dad daf dan dao dca dcc dcd dcf dcn dco dda ddc ddd ddf ddn ddo dfa dfc dfd dff dfn dfo dna dnc dnd dnf dnn dno doa doc dod dof don doo faa fac fad faf fan fao fca fcc fcd fcf fcn fco fda fdc fdd fdf fdn fdo ffa ffc ffd fff ffn ffo fna fnc fnd fnf fnn foa foc fof fon foo naa nac nad naf nan nao nca ncc ncd ncf ncn nco nda ndc ndd ndf ndn ndo nfa nfc nfd nff nfn nfo nna nnc nnf nnn nno no- noa noc nod nof non noo oaa oac oad oaf oan oao oc- oca occ ocd ocf ocn oco oda odc odd odf odn odo of- ofa ofc ofd off ofn ofo on- ona onc ond onf onn ono oo- ooa ooc ood oof oon ooo