a-a a-c a-z aaa aac aao aar aaz ac- aca acc aco acr acz aoa aoc aoo aor ar- ara arc aro arr arz az- aza azo azz c-- caa cac cao car caz cca ccc cco ccr ccz co- coa coc coo cor coz cra crc cro crr crz cz- czc czo oaa oac oao oar oc- oca occ oco ocr ocz oo- ooa ooc ooo oor or- ora orc oro orr orz oza ozo ozz ra- raa rac rao rar raz rca rcc rco rcr roa roc roo ror roz rra rrc rrr rza rzo zaa zac zao zar zaz zco zo- zoa zoc zoo zor zro zzr zzz