-er a-a a-b a-c a-t aaa aab aac aae aam aao aar aat ab- aba abb abc abe abm abo abr abt ac- aca acb acc ace acm aco acr act aea aeb aec aee aem aeo aer aet ama amb amc ame amm amo amr amt aoa aob aoc aoe aom aoo aor aot ar- ara arb arc are arm aro arr art at- ata atb atc ate atm ato atr att baa bab bac bae bam bao bar bat bba bbb bbc bbe bbm bbo bbr bbt bca bcb bcc bce bcm bco bcr bct be- bea beb bec bee bem beo ber bet bma bmb bmc bme bmm bmo bmr bmt boa bob boc boe bom boo bor bot bra brb bre brm bro brr brt bta btb btc bte btm bto btr btt c-- caa cab cac cae cam cao car cat cba cbb cbc cbe cbm cbo cbr cbt cca ccb ccc cce ccm cco ccr cct ce- cea ceb cec cee cem ceo cer cet cma cmb cmc cme cmm cmo cmr cmt co- coa cob coc coe com coo cor cot cra crb crc cre crm cro crr crt cta ctb ctc cte ctm cto ctr ctt eaa eab eac eae eam eao ear eat eba ebb ebc ebe ebm ebo ebr ebt ec- eca ecb ecc ece ecm eco ecr ect eea eeb eec eee eem eeo eer eet em- ema emb emc eme emm emo emr emt eo- eoa eob eoc eoe eom eoo eor eot era erb erc ere erm ero err ert eta etb etc ete etm eto etr ett m-o m-r maa mab mac mae mam mao mar mat mba mbb mbc mbe mbm mbo mbr mbt mc- mca mcb mcc mce mcm mco mcr mct mea meb mec mee mem meo mer met mma mmb mmc mme mmm mmo mmr mmt moa mob moc moe mom moo mor mot mra mrb mrc mre mrm mro mrr mrt mta mtb mtc mte mtm mto mtr mtt oaa oab oac oae oam oao oar oat ob- oba obb obc obe obm obo obr obt oc- oca ocb occ ocm oco ocr oct oea oeb oec oee oem oeo oer oet om- oma omb omc ome omm omo omr omt oo- ooa oob ooc oom ooo oor oot or- ora orb orc ore orm oro orr ort ot- ota otb otc ote otm oto otr ott ra- raa rab rac rae ram rao rar rat rba rbb rbc rbe rbm rbo rbr rbt rca rcb rcc rce rcm rco rcr rct re- rea reb rec ree rem reo rer ret rma rmb rmc rme rmm rmo rmr rmt roa rob roc roe rom roo ror rot rra rrb rrc rrm rrr rrt rta rtb rtc rte rtm rto rtr rtt taa tab tac tae tam tao tar tat tba tbb tbc tbe tbm tbo tbr tbt tca tcb tcc tce tcm tco tcr tct te- tea teb tec tee tem teo ter tet tma tmb tmc tme tmm tmo tmr tmt to- toa tob toc toe tom too tor tot tra trb trc tre trm tro trr trt tta ttb ttc tte ttm tto ttr ttt