a-a a-c aaa aac aak aan aao aar aas ac- aca acc ack acn aco acr acs aka akc akk akn ako akr aks an- ana anc ank ann ano anr ans aoa aoc aok aon aoo aor aos ar- ara arc ark arn aro arr ars as- asa asc ask asn aso asr ass c-- caa cac cak can cao car cas cca ccc cck ccn cco ccr ccs cka ckc cko cks cn- cna cnc cnn cno cnr cns co- coa coc cok con coo cor cos cra crc crk crn cro crr crs csa csc csk csn cso csr css ka- kaa kac kak kan kao kar kas kca kcc kck kcn kcr kcs kkc kkk kkn kkr kks kn- kna knc knk knn kno knr koa koc kok kon koo kor kos kra krc krk krn kro krr krs ksa ksc ksk ksn kso ksr kss naa nac nak nan nao nar nas nca ncc nck ncn nco ncr ncs nka nkc nkk nkn nko nkr nks nna nnc nnk nnn nno nns no- noa noc nok non noo nor nos nra nrc nrk nrn nro nrr nrs nsa nsc nsk nsn nso nsr nss oaa oac oak oan oao oar oas oc- oca occ ock ocn oco ocr ocs oka okc okk oko okr oks on- ona onc onk onn ono onr ons oo- ooa ooc ook oon ooo oor oos or- ora orc ork orn oro orr ors os- osa osc osk osn oso osr oss ra- raa rac rak ran rao rar ras rca rcc rcn rco rcr rcs rkc rkk rko rks rna rnc rnn rno rnr rns roa roc rok ron roo ror ros rra rrc rrk rrn rrr rrs rsa rsc rsk rsn rso rsr rss saa sac sak san sao sar sas sca scc sck scn sco scr scs sk- ska skc skk sko skr sks sna snc snk snn sno snr sns soa soc sok son soo sor sos sr- sra src srk srn sro srr srs ss- ssa ssc ssk ssn sso ssr sss