-er a-a a-b a-c a-t aaa aab aac aae aam aan aar aat ab- aba abb abc abe abm abn abr abt ac- aca acb acc ace acm acn acr act aea aeb aec aee aem aen aer aet ama amb amc ame amm amn amr amt an- ana anb anc ane anm ann anr ant ar- ara arb arc are arm arn arr art at- ata atb atc ate atm atn atr att baa bab bac bae bam ban bar bat bba bbb bbc bbe bbm bbn bbr bbt bca bcb bcc bce bcm bcn bcr bct be- bea beb bec bee bem ben ber bet bma bmb bmc bme bmm bmn bmr bmt bna bnb bnc bne bnn bnr bnt bra brb bre brm brn brr brt bta btb btc bte btm btn btr btt c-- caa cab cac cae cam can car cat cba cbb cbc cbe cbm cbn cbr cbt cca ccb ccc cce ccm ccn ccr cct ce- cea ceb cec cee cem cen cer cet cma cmb cmc cme cmm cmn cmr cmt cn- cna cnb cnc cne cnm cnn cnr cnt cra crb crc cre crm crn crr crt cta ctb ctc cte ctm ctn ctr ctt eaa eab eac eae eam ean ear eat eba ebb ebc ebe ebm ebn ebr ebt ec- eca ecb ecc ece ecm ecn ecr ect eea eeb eec eee eem een eer eet em- ema emb emc eme emm emn emr emt en- ena enb enc ene enm enn enr ent era erb erc ere erm ern err ert eta etb etc ete etm etn etr ett m-r maa mab mac mae mam man mar mat mba mbb mbc mbe mbm mbr mbt mc- mca mcb mcc mce mcm mcn mcr mct mea meb mec mee mem men mer met mma mmb mmc mme mmm mmn mmr mmt mna mnb mnc mne mnm mnn mnr mnt mra mrb mrc mre mrm mrn mrr mrt mta mtb mtc mte mtm mtn mtr mtt naa nab nac nae nam nan nar nat nba nbb nbc nbe nbm nbn nbr nbt nca ncb ncc nce ncm ncn ncr nct ne- nea neb nec nee nem nen ner net nma nmb nmc nme nmm nmn nmr nmt nna nnb nnc nne nnm nnn nnt nra nrb nrc nre nrm nrn nrr nrt nta ntb ntc nte ntm ntn ntr ntt ra- raa rab rac rae ram ran rar rat rba rbb rbc rbe rbm rbn rbr rbt rca rcb rcc rce rcm rcn rcr rct re- rea reb rec ree rem ren rer ret rma rmb rmc rme rmm rmn rmr rmt rna rnb rnc rnm rnn rnr rnt rra rrb rrc rrm rrn rrr rrt rta rtb rtc rte rtm rtn rtr rtt taa tab tac tae tam tan tar tat tba tbb tbc tbe tbm tbn tbr tbt tca tcb tcc tce tcm tcn tcr tct te- tea teb tec tee tem ten ter tet tma tmb tmc tme tmm tmn tmr tmt tna tnb tnc tne tnm tnn tnr tnt tra trb trc tre trm trn trr trt tta ttb ttc tte ttm ttn ttr ttt