a-a a-c a-z aaa aac aaf aao aar aay aaz ac- aca acc acf aco acr acy acz af- afa afc aff afo afr afy afz aoa aoc aof aoo aor ar- ara arc arf aro arr ary arz ay- aya ayc ayf ayo ayr ayz az- aza azf azo azy azz c-- caa cac caf cao car cay caz cca ccc ccf cco ccr ccz cfa cfc cff cfo cfr cfz co- coa coc cof coo cor coy coz cra crc crf cro crr cry crz cya cyc cyf cyo cyr cz- czc czo faa fac faf fao far fay faz fca fcc fcf fco fcr fcy fcz ffa ffc fff ffo ffr ffy ffz foa foc fof foo for foy foz fra frc frf fro frr fry fy- fya fyc fyo fyz oaa oac oaf oao oar oc- oca occ ocf oco ocr ocz of- ofa ofc off ofo ofr ofz oo- ooa ooc oof ooo oor or- ora orc orf oro orr ory orz oya oyo oza ozo ozz ra- raa rac raf rao rar ray raz rca rcc rcf rco rcr rfa rfc rff rfo rfr rfz roa roc rof roo ror roy roz rra rrc rrf rrr ry- rya ryc ryf ryo ryr ryy ryz rza rzo rzy yaa yac yaf yao yar yay yaz yca ycc ycf yco ycy yfa yfc yff yfr yoc yof yoo yor yoy yra yrc yrf yro yyc yyf yyy yyz yzf yzr yzy zaa zac zaf zao zar zay zaz zco zfa zfc zfr zfy zo- zoa zoc zof zoo zor zro zzr zzy zzz