-er a-a a-b a-c a-t aaa aab aac aad aae aar aas aat ab- aba abb abc abd abe abr abs abt ac- aca acb acc acd ace acr acs act ad- ada adb adc add ade adr ads adt aea aeb aec aed aee aer aes aet ar- ara arb arc ard are arr ars art as- asa asb asc asd ase asr ass ast at- ata atb atc atd ate atr ats att baa bab bac bad bae bar bas bat bba bbb bbc bbd bbe bbr bbs bbt bca bcb bcc bcd bce bcr bcs bct bda bdb bdc bdd bde bdr bds bdt be- bea beb bec bed bee ber bes bet bra brb brd bre brr brs brt bsa bsb bsc bsd bse bsr bss bst bta btb btc btd bte btr bts btt c-- caa cab cac cad cae car cas cat cba cbb cbc cbd cbe cbr cbs cbt cca ccb ccc ccd cce ccr ccs cct cda cdb cdc cdd cde cdr cds cdt ce- cea ceb cec ced cee cer ces cet cra crb crc crd cre crr crs crt csa csb csc csd cse csr css cst cta ctb ctc ctd cte ctr cts ctt daa dab dac dad dae dar das dat dba dbb dbc dbd dbe dbr dbs dbt dca dcb dcc dcd dce dcr dcs dct dda ddb ddc ddd dde ddr dds ddt de- dea deb dec ded dee der des det dra drb drc drd dre drr drs drt dsa dsb dsc dsd dse dsr dss dst dta dtb dtc dtd dte dtr dts dtt eaa eab eac ead eae ear eas eat eba ebb ebc ebd ebe ebr ebs ebt ec- eca ecb ecc ecd ece ecr ecs ect ed- eda edb edc edd ede edr eds edt eea eeb eec eed eee eer ees eet era erb erc erd ere err ers ert es- esa esb esc esd ese esr ess est eta etb etc etd ete etr ets ett ra- raa rab rac rad rae rar ras rat rba rbb rbc rbd rbe rbr rbs rbt rca rcb rcc rcd rce rcr rcs rct rda rdb rdc rdd rde rdr rds rdt re- rea reb rec red ree rer res ret rra rrb rrc rrd rrr rrs rrt rsa rsb rsc rsd rse rsr rss rst rta rtb rtc rtd rte rtr rts rtt saa sab sac sad sae sar sas sat sba sbb sbc sbd sbe sbr sbs sbt sca scb scc scd sce scr scs sct sda sdb sdc sdd sde sdr sds sdt se- sea seb sec sed see ser ses set sr- sra srb src srd sre srr srs srt ss- ssa ssb ssc ssd sse ssr sss sst sta stb stc std ste str sts stt taa tab tac tad tae tar tas tat tba tbb tbc tbd tbe tbr tbs tbt tca tcb tcc tcd tce tcr tcs tct tda tdb tdc tdd tde tdr tds tdt te- tea teb tec ted tee ter tes tet tra trb trc trd tre trr trs trt tsa tsb tsc tsd tse tsr tss tst tta ttb ttc ttd tte ttr tts ttt