a-a aaa aaf aak aan aao aar aas af- afa aff afk afn afo afr afs aka akk akn ako akr aks an- ana anf ank ann ano anr ans aoa aof aok aon aoo aor aos ar- ara arf ark arn aro arr ars as- asa asf ask asn aso asr ass faa faf fak fan fao far fas ffa fff ffk ffn ffo ffr ffs fka fkf fkk fna fnf fnk fnn fnr fns foa fof fok fon foo for fos fra frf frk frn fro frr frs fsa fsf fsk fsn fso fsr fss ka- kaa kaf kak kan kao kar kas kfa kff kfo kfs kkk kkn kkr kks kn- kna knf knk knn kno knr koa kof kok kon koo kor kos kra krf krk krn kro krr krs ksa ksf ksk ksn kso ksr kss naa naf nak nan nao nar nas nfa nff nfk nfn nfo nfr nfs nka nkf nkk nkn nko nkr nks nna nnf nnk nnn nno nns no- noa nof nok non noo nor nos nra nrf nrk nrn nro nrr nrs nsa nsf nsk nsn nso nsr nss oaa oaf oak oan oao oar oas of- ofa off ofn ofo ofr ofs oka okk oko okr oks on- ona onf onk onn ono onr ons oo- ooa oof ook oon ooo oor oos or- ora orf ork orn oro orr ors os- osa osf osk osn oso osr oss ra- raa raf rak ran rao rar ras rfa rff rfk rfn rfo rfr rfs rkf rkk rko rks rna rnn rno rnr rns roa rof rok ron roo ror ros rra rrf rrk rrn rrr rrs rsa rsf rsk rsn rso rsr rss saa saf sak san sao sar sas sfa sff sfk sfn sfo sfr sfs sk- ska skf skk sko skr sks sna snf snk snn sno snr sns soa sof sok son soo sor sos sr- sra srf srk srn sro srr srs ss- ssa ssf ssk ssn sso ssr sss