-er a-a a-b aaa aab aae aam aan aao aar ab- aba abb abe abm abn abo abr aea aeb aee aem aen aeo aer ama amb ame amm amn amo amr an- ana anb ane anm ann ano anr aoa aob aoe aom aon aoo aor ar- ara arb are arm arn aro arr baa bab bae bam ban bao bar bba bbb bbe bbm bbn bbo bbr be- bea beb bee bem ben beo ber bma bmb bme bmm bmn bmo bmr bna bnb bne bnn bno bnr boa bob boe bom bon boo bor bra brb bre brm brn bro brr eaa eab eae eam ean eao ear eba ebb ebe ebm ebn ebo ebr eea eeb eee eem een eeo eer em- ema emb eme emm emn emo emr en- ena enb ene enm enn eno enr eo- eoa eob eoe eom eon eoo eor era erb ere erm ern ero err m-o m-r maa mab mae mam man mao mar mba mbb mbe mbm mbo mbr mea meb mee mem men meo mer mma mmb mme mmm mmn mmo mmr mna mnb mne mnm mnn mno mnr moa mob moe mom mon moo mor mra mrb mre mrm mrn mro mrr naa nab nae nam nan nao nar nba nbb nbe nbm nbn nbo nbr ne- nea neb nee nem nen neo ner nma nmb nme nmm nmn nmo nmr nna nnb nne nnm nnn nno no- noa nob noe nom non noo nor nra nrb nre nrm nrn nro nrr oaa oab oae oam oan oao oar ob- oba obb obe obm obn obo obr oea oeb oee oem oen oeo oer om- oma omb ome omm omn omo omr on- ona onb one onn ono onr oo- ooa oob oom oon ooo oor or- ora orb ore orm orn oro orr ra- raa rab rae ram ran rao rar rba rbb rbe rbm rbn rbo rbr re- rea reb ree rem ren reo rer rma rmb rme rmm rmn rmo rmr rna rnb rnm rnn rno rnr roa rob roe rom ron roo ror rra rrb rrm rrn rrr