-er a-a a-b aaa aab aae aam aao aap aar aas ab- aba abb abe abm abo abp abr abs aea aeb aee aem aeo aep aer aes ama amb ame amm amo amp amr ams aoa aob aoe aom aoo aop aor aos ap- apa apb ape apm apo app apr aps ar- ara arb are arm aro arp arr ars as- asa asb ase asm aso asp asr ass b-p baa bab bae bam bao bap bar bas bba bbb bbe bbm bbo bbp bbr bbs be- bea beb bee bem beo bep ber bes bma bmb bme bmm bmo bmp bmr bms boa bob boe bom boo bop bor bos bpa bpb bpe bpm bpo bpp bpr bps bra brb bre brm bro brp brr brs bsa bsb bse bsm bso bsp bsr bss eaa eab eae eam eao eap ear eas eba ebb ebe ebm ebo ebp ebr ebs eea eeb eee eem eeo eep eer ees em- ema emb eme emm emo emp emr ems eo- eoa eob eoe eom eoo eop eor eos ep- epa epb epe epm epo epp epr eps era erb ere erm ero erp err ers es- esa esb ese esm eso esp esr ess m-o m-r maa mab mae mam mao map mar mas mba mbb mbe mbm mbo mbp mbr mbs mea meb mee mem meo mep mer mes mma mmb mme mmm mmo mmp mmr mms moa mob moe mom moo mop mor mos mpa mpb mpe mpm mpo mpp mpr mps mra mrb mre mrm mro mrp mrr mrs msa msb mse msm mso msp msr mss oaa oab oae oam oao oap oar oas ob- oba obb obe obm obo obp obr obs oea oeb oee oem oeo oep oer oes om- oma omb ome omm omo omp omr oms oo- ooa oob oom ooo oop oor oos op- opa opb ope opm opo opp opr ops or- ora orb ore orm oro orp orr ors os- osa osb ose osm oso osp osr oss p-p paa pab pae pam pao pap par pas pba pbb pbe pbm pbo pbp pbr pbs pea peb pee pem peo pep per pes pma pmb pme pmm pmo pmp pmr pms poa pob poe pom poo pop por pos ppa ppb ppe ppm ppo ppp ppr pps pra prb pre prm pro prp prr prs ps- psa psb pse psm pso psp psr pss ra- raa rab rae ram rao rap rar ras rba rbb rbe rbm rbo rbp rbr rbs re- rea reb ree rem reo rep rer res rma rmb rme rmm rmo rmp rmr rms roa rob roe rom roo rop ror ros rpa rpb rpe rpm rpo rpp rpr rps rra rrb rrm rrp rrr rrs rsa rsb rse rsm rso rsp rsr rss saa sab sae sam sao sap sar sas sba sbb sbe sbm sbo sbp sbr sbs se- sea seb see sem seo sep ser ses sma smb sme smm smo smp smr sms soa sob soe som soo sop sor sos spa spb spe spm spo spp spr sps sr- sra srb sre srm sro srp srr srs ss- ssa ssb sse ssm sso ssp ssr sss