a-a aaa aak aao aar aas aka akk ako akr aks aoa aok aoo aor aos ar- ara ark aro arr ars as- asa ask aso asr ass ka- kaa kak kao kar kas kkk kkr kks koa kok koo kor kos kra krk kro krr krs ksa ksk kso ksr kss oaa oak oao oar oas oka okk oko okr oks oo- ooa ook ooo oor oos or- ora ork oro orr ors os- osa osk oso osr oss ra- raa rak rao rar ras rkk rko rks roa rok roo ror ros rra rrk rrr rrs rsa rsk rso rsr rss saa sak sao sar sas sk- ska skk sko skr sks soa sok soo sor sos sr- sra srk sro srr srs ss- ssa ssk sso ssr sss