-er a-a a-b aaa aab aae aam aao aap aar ab- aba abb abe abm abo abp abr aea aeb aee aem aeo aep aer ama amb ame amm amo amp amr aoa aob aoe aom aoo aop aor ap- apa apb ape apm apo app apr ar- ara arb are arm aro arp arr b-p baa bab bae bam bao bap bar bba bbb bbe bbm bbo bbp bbr be- bea beb bee bem beo bep ber bma bmb bme bmm bmo bmp bmr boa bob boe bom boo bop bor bpa bpb bpe bpm bpo bpp bpr bra brb bre brm bro brp brr eaa eab eae eam eao eap ear eba ebb ebe ebm ebo ebp ebr eea eeb eee eem eeo eep eer em- ema emb eme emm emo emp emr eo- eoa eob eoe eom eoo eop eor ep- epa epb epe epm epo epp epr era erb ere erm ero erp err m-o m-r maa mab mae mam mao map mar mba mbb mbe mbm mbo mbp mbr mea meb mee mem meo mep mer mma mmb mme mmm mmo mmp mmr moa mob moe mom moo mop mor mpa mpb mpe mpm mpo mpp mpr mra mrb mre mrm mro mrp mrr oaa oab oae oam oao oap oar ob- oba obb obe obm obo obp obr oea oeb oee oem oeo oep oer om- oma omb ome omm omo omp omr oo- ooa oob oom ooo oop oor op- opa opb ope opm opo opp opr or- ora orb ore orm oro orp orr p-p paa pab pae pam pao pap par pba pbb pbe pbm pbo pbp pbr pea peb pee pem peo pep per pma pmb pme pmm pmo pmp pmr poa pob poe pom poo pop por ppa ppb ppe ppm ppo ppp ppr pra prb pre prm pro prp prr ra- raa rab rae ram rao rap rar rba rbb rbe rbm rbo rbp rbr re- rea reb ree rem reo rep rer rma rmb rme rmm rmo rmp rmr roa rob roe rom roo rop ror rpa rpb rpe rpm rpo rpp rpr rra rrb rrm rrp rrr