-er a-a a-b a-c a-t aaa aab aac aae aam aar aas aat ab- aba abb abc abe abm abr abs abt ac- aca acb acc ace acm acr acs act aea aeb aec aee aem aer aes aet ama amb amc ame amm amr ams amt ar- ara arb arc are arm arr ars art as- asa asb asc ase asm asr ass ast at- ata atb atc ate atm atr ats att baa bab bac bae bam bar bas bat bba bbb bbc bbe bbm bbr bbs bbt bca bcb bcc bce bcm bcr bcs bct be- bea beb bec bee bem ber bes bet bma bmb bmc bme bmm bmr bms bmt bra brb bre brm brr brs brt bsa bsb bsc bse bsm bsr bss bst bta btb btc bte btm btr bts btt c-- caa cab cac cae cam car cas cat cba cbb cbc cbe cbm cbr cbs cbt cca ccb ccc cce ccm ccr ccs cct ce- cea ceb cec cee cem cer ces cet cma cmb cmc cme cmm cmr cms cmt cra crb crc cre crm crr crs crt csa csb csc cse csm csr css cst cta ctb ctc cte ctm ctr cts ctt eaa eab eac eae eam ear eas eat eba ebb ebc ebe ebm ebr ebs ebt ec- eca ecb ecc ece ecm ecr ecs ect eea eeb eec eee eem eer ees eet em- ema emb emc eme emm emr ems emt era erb erc ere erm err ers ert es- esa esb esc ese esm esr ess est eta etb etc ete etm etr ets ett m-r maa mab mac mae mam mar mas mat mba mbb mbc mbe mbm mbr mbs mbt mc- mca mcb mcc mce mcm mcr mcs mct mea meb mec mee mem mer mes met mma mmb mmc mme mmm mmr mms mmt mra mrb mrc mre mrm mrr mrs mrt msa msb msc mse msm msr mss mst mta mtb mtc mte mtm mtr mts mtt ra- raa rab rac rae ram rar ras rat rba rbb rbc rbe rbm rbr rbs rbt rca rcb rcc rce rcm rcr rcs rct re- rea reb rec ree rem rer res ret rma rmb rmc rme rmm rmr rms rmt rra rrb rrc rrm rrr rrs rrt rsa rsb rsc rse rsm rsr rss rst rta rtb rtc rte rtm rtr rts rtt saa sab sac sae sam sar sas sat sba sbb sbc sbe sbm sbr sbs sbt sca scb scc sce scm scr scs sct se- sea seb sec see sem ser ses set sma smb smc sme smm smr sms smt sr- sra srb src sre srm srr srs srt ss- ssa ssb ssc sse ssm ssr sss sst sta stb stc ste stm str sts stt taa tab tac tae tam tar tas tat tba tbb tbc tbe tbm tbr tbs tbt tca tcb tcc tce tcm tcr tcs tct te- tea teb tec tee tem ter tes tet tma tmb tmc tme tmm tmr tms tmt tra trb trc tre trm trr trs trt tsa tsb tsc tse tsm tsr tss tst tta ttb ttc tte ttm ttr tts ttt