-er a-a a-c a-t aaa aac aae aao aar aas aat ac- aca acc ace aco acr acs act aea aec aee aeo aer aes aet aoa aoc aoe aoo aor aos aot ar- ara arc are aro arr ars art as- asa asc ase aso asr ass ast at- ata atc ate ato atr ats att c-- caa cac cae cao car cas cat cca ccc cce cco ccr ccs cct ce- cea cec cee ceo cer ces cet co- coa coc coe coo cor cos cot cra crc cre cro crr crs crt csa csc cse cso csr css cst cta ctc cte cto ctr cts ctt eaa eac eae eao ear eas eat ec- eca ecc ece eco ecr ecs ect eea eec eee eeo eer ees eet eo- eoa eoc eoe eoo eor eos eot era erc ere ero err ers ert es- esa esc ese eso esr ess est eta etc ete eto etr ets ett oaa oac oae oao oar oas oat oc- oca occ oco ocr ocs oct oea oec oee oeo oer oes oet oo- ooa ooc ooo oor oos oot or- ora orc ore oro orr ors ort os- osa osc ose oso osr oss ost ot- ota otc ote oto otr ots ott ra- raa rac rae rao rar ras rat rca rcc rce rco rcr rcs rct re- rea rec ree reo rer res ret roa roc roe roo ror ros rot rra rrc rrr rrs rrt rsa rsc rse rso rsr rss rst rta rtc rte rto rtr rts rtt saa sac sae sao sar sas sat sca scc sce sco scr scs sct se- sea sec see seo ser ses set soa soc soe soo sor sos sot sr- sra src sre sro srr srs srt ss- ssa ssc sse sso ssr sss sst sta stc ste sto str sts stt taa tac tae tao tar tas tat tca tcc tce tco tcr tcs tct te- tea tec tee teo ter tes tet to- toa toc toe too tor tos tot tra trc tre tro trr trs trt tsa tsc tse tso tsr tss tst tta ttc tte tto ttr tts ttt