-er a-a a-c a-t aaa aac aad aae aar aas aat ac- aca acc acd ace acr acs act ad- ada adc add ade adr ads adt aea aec aed aee aer aes aet ar- ara arc ard are arr ars art as- asa asc asd ase asr ass ast at- ata atc atd ate atr ats att c-- caa cac cad cae car cas cat cca ccc ccd cce ccr ccs cct cda cdc cdd cde cdr cds cdt ce- cea cec ced cee cer ces cet cra crc crd cre crr crs crt csa csc csd cse csr css cst cta ctc ctd cte ctr cts ctt daa dac dad dae dar das dat dca dcc dcd dce dcr dcs dct dda ddc ddd dde ddr dds ddt de- dea dec ded dee der des det dra drc drd dre drr drs drt dsa dsc dsd dse dsr dss dst dta dtc dtd dte dtr dts dtt eaa eac ead eae ear eas eat ec- eca ecc ecd ece ecr ecs ect ed- eda edc edd ede edr eds edt eea eec eed eee eer ees eet era erc erd ere err ers ert es- esa esc esd ese esr ess est eta etc etd ete etr ets ett ra- raa rac rad rae rar ras rat rca rcc rcd rce rcr rcs rct rda rdc rdd rde rdr rds rdt re- rea rec red ree rer res ret rra rrc rrd rrr rrs rrt rsa rsc rsd rse rsr rss rst rta rtc rtd rte rtr rts rtt saa sac sad sae sar sas sat sca scc scd sce scr scs sct sda sdc sdd sde sdr sds sdt se- sea sec sed see ser ses set sr- sra src srd sre srr srs srt ss- ssa ssc ssd sse ssr sss sst sta stc std ste str sts stt taa tac tad tae tar tas tat tca tcc tcd tce tcr tcs tct tda tdc tdd tde tdr tds tdt te- tea tec ted tee ter tes tet tra trc trd tre trr trs trt tsa tsc tsd tse tsr tss tst tta ttc ttd tte ttr tts ttt