a-a a-c aaa aac aak aao aap aar aas ac- aca acc ack aco acp acr acs aka akc akk ako akp akr aks aoa aoc aok aoo aop aor aos ap- apa apc apk apo app apr aps ar- ara arc ark aro arp arr ars as- asa asc ask aso asp asr ass c-- caa cac cak cao cap car cas cca ccc cck cco ccp ccr ccs cka ckc cko cks co- coa coc cok coo cop cor cos cpa cpc cpk cpo cpp cpr cps cra crc crk cro crp crr crs csa csc csk cso csp csr css ka- kaa kac kak kao kap kar kas kca kcc kck kcp kcr kcs kkc kkk kkp kkr kks koa koc kok koo kop kor kos kpa kpc kpk kpo kpp kpr kps kra krc krk kro krp krr krs ksa ksc ksk kso ksp ksr kss oaa oac oak oao oap oar oas oc- oca occ ock oco ocp ocr ocs oka okc okk oko okp okr oks oo- ooa ooc ook ooo oop oor oos op- opa opc opk opo opp opr ops or- ora orc ork oro orp orr ors os- osa osc osk oso osp osr oss p-p paa pac pak pao pap par pas pca pcc pck pco pcp pcr pcs pka pkc pko pkp pkr pks poa poc pok poo pop por pos ppa ppc ppk ppo ppp ppr pps pra prc prk pro prp prr prs ps- psa psc psk pso psp psr pss ra- raa rac rak rao rap rar ras rca rcc rco rcp rcr rcs rkc rkk rko rkp rks roa roc rok roo rop ror ros rpa rpc rpk rpo rpp rpr rps rra rrc rrk rrp rrr rrs rsa rsc rsk rso rsp rsr rss saa sac sak sao sap sar sas sca scc sck sco scp scr scs sk- ska skc skk sko skp skr sks soa soc sok soo sop sor sos spa spc spk spo spp spr sps sr- sra src srk sro srp srr srs ss- ssa ssc ssk sso ssp ssr sss