-er a-a a-b aaa aab aae aag aam aan aao aar ab- aba abb abe abg abm abn abo abr aea aeb aee aeg aem aen aeo aer ag- aga agb age agg agm agn ago agr ama amb ame amg amm amn amo amr an- ana anb ane ang anm ann ano anr aoa aob aoe aog aom aon aoo aor ar- ara arb are arg arm arn aro arr baa bab bae bag bam ban bao bar bba bbb bbe bbg bbm bbn bbo bbr be- bea beb bee beg bem ben beo ber bga bgb bge bgg bgm bgn bgo bgr bma bmb bme bmg bmm bmn bmo bmr bna bnb bne bng bnn bno bnr boa bob boe bog bom bon boo bor bra brb bre brg brm brn bro brr eaa eab eae eag eam ean eao ear eba ebb ebe ebg ebm ebn ebo ebr eea eeb eee eeg eem een eeo eer ega egb ege egg egm egn ego egr em- ema emb eme emg emm emn emo emr en- ena enb ene eng enm enn eno enr eo- eoa eob eoe eog eom eon eoo eor era erb ere erg erm ern ero err gaa gab gae gag gam gan gao gar gba gbe gbg gbm gbn gbo gbr ge- gea geb gee geg gem gen geo ger gga ggb ggg ggm ggn ggo ggr gma gmb gme gmg gmm gmn gmo gmr gna gnb gne gnm gnn gno gnr goa gob goe gog gom gon goo gor gra grb gre grg grm grn gro grr m-o m-r maa mab mae mag mam man mao mar mba mbb mbe mbg mbm mbo mbr mea meb mee meg mem men meo mer mga mgb mge mgm mgn mgo mgr mma mmb mme mmg mmm mmn mmo mmr mna mnb mne mng mnm mnn mno mnr moa mob moe mog mom mon moo mor mra mrb mre mrg mrm mrn mro mrr naa nab nae nag nam nan nao nar nba nbb nbe nbg nbm nbn nbo nbr ne- nea neb nee neg nem nen neo ner nga ngb nge ngg ngm ngn ngo nma nmb nme nmg nmm nmn nmo nmr nna nnb nne nng nnm nnn nno no- noa nob noe nog nom non noo nor nra nrb nre nrg nrm nrn nro nrr oaa oab oae oag oam oan oao oar ob- oba obb obe obg obm obn obo obr oea oeb oee oeg oem oen oeo oer oga oge ogg ogn ogo om- oma omb ome omg omm omn omo omr on- ona onb one ong onn ono onr oo- ooa oob oog oom oon ooo oor or- ora orb ore org orm orn oro orr ra- raa rab rae rag ram ran rao rar rba rbb rbe rbg rbm rbn rbo rbr re- rea reb ree reg rem ren reo rer rga rgb rge rgg rgn rgo rgr rma rmb rme rmg rmm rmn rmo rmr rna rnb rng rnm rnn rno rnr roa rob roe rog rom ron roo ror rra rrb rrg rrm rrn rrr