-er a-a a-c a-t aaa aac aae aak aap aar aas aat ac- aca acc ace ack acp acr acs act aea aec aee aek aep aer aes aet aka akc ake akk akp akr aks ap- apa apc ape apk app apr aps apt ar- ara arc are ark arp arr ars art as- asa asc ase ask asp asr ass ast at- ata atc ate atp atr ats att c-- caa cac cae cak cap car cas cat cca ccc cce cck ccp ccr ccs cct ce- cea cec cee cek cep cer ces cet cka ckc cks ckt cpa cpc cpe cpk cpp cpr cps cpt cra crc cre crk crp crr crs crt csa csc cse csk csp csr css cst cta ctc cte ctk ctp ctr cts ctt eaa eac eae eak eap ear eas eat ec- eca ecc ece eck ecr ecs ect eea eec eee eek eep eer ees eet eka ekc eke ekp ekr eks ekt ep- epa epc epe epp epr eps ept era erc ere erk erp err ers ert es- esa esc ese esk esp esr ess est eta etc ete etk etp etr ets ett k-t ka- kaa kac kae kak kap kar kas kat kca kcc kce kck kcp kcr kcs kct ke- kea kec kee kek kep ker kes ket kkc kke kkk kkp kkr kks kkt kpa kpc kpe kpk kpp kpr kps kpt kra krc krk krp krr krs krt ksa ksc kse ksk ksp ksr kss kst kta ktc kte ktk ktp ktr kts ktt p-p paa pac pae pak pap par pas pat pca pcc pce pck pcp pcr pcs pct pea pec pee pek pep per pes pet pka pkc pke pkp pkr pks pkt ppa ppc ppe ppk ppp ppr pps ppt pra prc pre prk prp prr prs prt ps- psa psc pse psk psp psr pss pst pt- pta ptc pte ptk ptp ptr pts ptt ra- raa rac rae rak rap rar ras rat rca rcc rce rcp rcr rcs rct re- rea rec ree rek rep rer res ret rkc rke rkk rkp rks rkt rpa rpc rpe rpk rpp rpr rps rpt rra rrc rrk rrp rrr rrs rrt rsa rsc rse rsk rsp rsr rss rst rta rtc rte rtk rtp rtr rts rtt saa sac sae sak sap sar sas sat sca scc sce sck scp scr scs sct se- sea sec see sek sep ser ses set sk- ska skc ske skk skp skr sks skt spa spc spe spk spp spr sps spt sr- sra src sre srk srp srr srs srt ss- ssa ssc sse ssk ssp ssr sss sst sta stc ste stk stp str sts stt taa tac tae tak tap tar tas tat tca tcc tce tck tcp tcr tcs tct te- tea tec tee tek tep ter tes tet tka tkc tke tkk tkp tkr tks tkt tpa tpc tpe tpk tpp tpr tps tpt tra trc tre trk trp trr trs trt tsa tsc tse tsk tsp tsr tss tst tta ttc tte ttk ttp ttr tts ttt