-er a-a a-b a-t aaa aab aae aam aan aao aar aat ab- aba abb abe abm abn abo abr abt aea aeb aee aem aen aeo aer aet ama amb ame amm amn amo amr amt an- ana anb ane anm ann ano anr ant aoa aob aoe aom aon aoo aor aot ar- ara arb are arm arn aro arr art at- ata atb ate atm atn ato atr att baa bab bae bam ban bao bar bat bba bbb bbe bbm bbn bbo bbr bbt be- bea beb bee bem ben beo ber bet bma bmb bme bmm bmn bmo bmr bmt bna bnb bne bnn bno bnr bnt boa bob boe bom bon boo bor bot bra brb bre brm brn bro brr brt bta btb bte btm btn bto btr btt eaa eab eae eam ean eao ear eat eba ebb ebe ebm ebn ebo ebr ebt eea eeb eee eem een eeo eer eet em- ema emb eme emm emn emo emr emt en- ena enb ene enm enn eno enr ent eo- eoa eob eoe eom eon eoo eor eot era erb ere erm ern ero err ert eta etb ete etm etn eto etr ett m-o m-r maa mab mae mam man mao mar mat mba mbb mbe mbm mbo mbr mbt mea meb mee mem men meo mer met mma mmb mme mmm mmn mmo mmr mmt mna mnb mne mnm mnn mno mnr mnt moa mob moe mom mon moo mor mot mra mrb mre mrm mrn mro mrr mrt mta mtb mte mtm mtn mto mtr mtt naa nab nae nam nan nao nar nat nba nbb nbe nbm nbn nbo nbr nbt ne- nea neb nee nem nen neo ner net nma nmb nme nmm nmn nmo nmr nmt nna nnb nne nnm nnn nno nnt no- noa nob noe nom non noo nor not nra nrb nre nrm nrn nro nrr nrt nta ntb nte ntm ntn nto ntr ntt oaa oab oae oam oan oao oar oat ob- oba obb obe obm obn obo obr obt oea oeb oee oem oen oeo oer oet om- oma omb ome omm omn omo omr omt on- ona onb one onn ono onr ont oo- ooa oob oom oon ooo oor oot or- ora orb ore orm orn oro orr ort ot- ota otb ote otm otn oto otr ott ra- raa rab rae ram ran rao rar rat rba rbb rbe rbm rbn rbo rbr rbt re- rea reb ree rem ren reo rer ret rma rmb rme rmm rmn rmo rmr rmt rna rnb rnm rnn rno rnr rnt roa rob roe rom ron roo ror rot rra rrb rrm rrn rrr rrt rta rtb rte rtm rtn rto rtr rtt taa tab tae tam tan tao tar tat tba tbb tbe tbm tbn tbo tbr tbt te- tea teb tee tem ten teo ter tet tma tmb tme tmm tmn tmo tmr tmt tna tnb tne tnm tnn tno tnr tnt to- toa tob toe tom ton too tor tot tra trb tre trm trn tro trr trt tta ttb tte ttm ttn tto ttr ttt