-er a-a a-b a-t aaa aab aae aam aar aas aat aax ab- aba abb abe abm abr abs abt abx aea aeb aee aem aer aes aet aex ama amb ame amm amr ams amt amx ar- ara arb are arm arr ars art arx as- asa asb ase asm asr ass ast asx at- ata atb ate atm atr ats att atx ax- axa axe axm axr axs axt axx baa bab bae bam bar bas bat bax bba bbb bbe bbm bbr bbs bbt bbx be- bea beb bee bem ber bes bet bex bma bmb bme bmm bmr bms bmt bmx bra brb bre brm brr brs brt brx bsa bsb bse bsm bsr bss bst bsx bta btb bte btm btr bts btt btx bxb bxm bxx eaa eab eae eam ear eas eat eax eba ebb ebe ebm ebr ebs ebt ebx eea eeb eee eem eer ees eet eex em- ema emb eme emm emr ems emt emx era erb ere erm err ers ert es- esa esb ese esm esr ess est esx eta etb ete etm etr ets ett etx ex- exa exe exr exs ext exx m-r maa mab mae mam mar mas mat max mba mbb mbe mbm mbr mbs mbt mbx mea meb mee mem mer mes met mex mma mmb mme mmm mmr mms mmt mmx mra mrb mre mrm mrr mrs mrt mrx msa msb mse msm msr mss mst msx mta mtb mte mtm mtr mts mtt mtx mxa mxr mxs ra- raa rab rae ram rar ras rat rax rba rbb rbe rbm rbr rbs rbt rbx re- rea reb ree rem rer res ret rex rma rmb rme rmm rmr rms rmt rmx rra rrb rrm rrr rrs rrt rsa rsb rse rsm rsr rss rst rsx rta rtb rte rtm rtr rts rtt rtx rxr rxs saa sab sae sam sar sas sat sax sba sbb sbe sbm sbr sbs sbt sbx se- sea seb see sem ser ses set sex sma smb sme smm smr sms smt smx sr- sra srb sre srm srr srs srt srx ss- ssa ssb sse ssm ssr sss sst ssx sta stb ste stm str sts stt stx sxm sxs sxt t-x taa tab tae tam tar tas tat tax tba tbb tbe tbm tbr tbs tbt te- tea teb tee tem ter tes tet tex tma tmb tme tmm tmr tms tmt tmx tra trb tre trm trr trs trt trx tsa tsb tse tsm tsr tss tst tsx tta ttb tte ttm ttr tts ttt ttx txe txs txt xaa xam xar xas xat xbe xbr xbx xee xem xer xes xet xex xma xmm xmr xms xmt xmx xrt xrx xsa xsb xsm xss xst xtm xtr xts xtx xxx