-er a-a a-c aaa aac aae aak aao aar aas aav ac- aca acc ace ack aco acr acs acv aea aec aee aek aeo aer aes aev aka akc ake akk ako akr aks akv aoa aoc aoe aok aoo aor aos aov ar- ara arc are ark aro arr ars arv as- asa asc ase ask aso asr ass asv av- ava avc ave avk avo avr avs c-- caa cac cae cak cao car cas cav cca ccc cce cck cco ccr ccs ccv ce- cea cec cee cek ceo cer ces cev cka ckc cko cks co- coa coc coe cok coo cor cos cov cra crc cre crk cro crr crs crv csa csc cse csk cso csr css csv cva cvc cve cvk cvo cvr cvs cvv eaa eac eae eak eao ear eas eav ec- eca ecc ece eck eco ecr ecs ecv eea eec eee eek eeo eer ees eev eka ekc eke eko ekr eks ekv eo- eoa eoc eoe eok eoo eor eos era erc ere erk ero err ers erv es- esa esc ese esk eso esr ess esv eva evc eve evo evr evs evv ka- kaa kac kae kak kao kar kas kav kca kcc kce kck kcr kcs ke- kea kec kee kek keo ker kes kev kkc kke kkk kkr kks kkv koa koc koe kok koo kor kos kra krc krk kro krr krs krv ksa ksc kse ksk kso ksr kss ksv kva kvk kvo kvr kvs kvv oaa oac oae oak oao oar oas oav oc- oca occ ock oco ocr ocs ocv oea oec oee oeo oer oes oka okc oke okk oko okr oks oo- ooa ooc ook ooo oor oos oov or- ora orc ore ork oro orr ors orv os- osa osc ose osk oso osr oss osv ov- ova ovc ove ovo ovs ovv ra- raa rac rae rak rao rar ras rav rca rcc rce rco rcr rcs rcv re- rea rec ree rek reo rer res rev rkc rke rkk rko rks rkv roa roc roe rok roo ror ros rov rra rrc rrk rrr rrs rsa rsc rse rsk rso rsr rss rsv rva rvc rve rvo rvr rvs rvv saa sac sae sak sao sar sas sav sca scc sce sck sco scr scs scv se- sea sec see sek seo ser ses sev sk- ska skc ske skk sko skr sks soa soc soe sok soo sor sos sov sr- sra src sre srk sro srr srs srv ss- ssa ssc sse ssk sso ssr sss ssv sva svc sve svk svo svr svs svv v-a v-e vaa vac vae vak vao var vas vav vca vcc vce vco vcr vcs vea vec vee vek veo ver ves vka voa voc voe vok voo vor vos vov vra vrc vre vrk vrr vrs vsa vsc vse vsk vso vsr vss vsv vva vvc vvo vvr vvs vvv