-er a-a a-b aaa aab aae aag aan aao aap aar aas ab- aba abb abe abg abn abo abp abr abs aea aeb aee aeg aen aeo aep aer aes ag- aga agb age agg agn ago agp agr ags an- ana anb ane ang ann ano anp anr ans aoa aob aoe aog aon aoo aop aor aos ap- apa apb ape apg apn apo app apr aps ar- ara arb are arg arn aro arp arr ars as- asa asb ase asg asn aso asp asr ass b-p baa bab bae bag ban bao bap bar bas bba bbb bbe bbg bbn bbo bbp bbr bbs be- bea beb bee beg ben beo bep ber bes bga bgb bge bgg bgn bgo bgp bgr bgs bna bnb bne bng bnn bno bnp bnr bns boa bob boe bog bon boo bop bor bos bpa bpb bpe bpg bpn bpo bpp bpr bps bra brb bre brg brn bro brp brr brs bsa bsb bse bsg bsn bso bsp bsr bss eaa eab eae eag ean eao eap ear eas eba ebb ebe ebg ebn ebo ebp ebr ebs eea eeb eee eeg een eeo eep eer ees ega egb ege egg egn ego egp egr egs en- ena enb ene eng enn eno enp enr ens eo- eoa eob eoe eog eon eoo eop eor eos ep- epa epb epe epg epn epo epp epr eps era erb ere erg ern ero erp err ers es- esa esb ese esg esn eso esp esr ess g-p gaa gab gae gag gan gao gap gar gas gba gbe gbg gbn gbo gbp gbr gbs ge- gea geb gee geg gen geo gep ger ges gga ggb ggg ggn ggo ggp ggr ggs gna gnb gne gnn gno gnp gnr gns goa gob goe gog gon goo gop gor gos gpa gpb gpe gpg gpn gpo gpp gpr gps gra grb gre grg grn gro grp grr grs gsa gsb gse gsg gsn gso gsp gsr gss naa nab nae nag nan nao nap nar nas nba nbb nbe nbg nbn nbo nbp nbr nbs ne- nea neb nee neg nen neo nep ner nes nga ngb nge ngg ngn ngo ngp ngs nna nnb nne nng nnn nno nnp nns no- noa nob noe nog non noo nop nor nos npa npb npe npg npn npo npp npr nps nra nrb nre nrg nrn nro nrp nrr nrs nsa nsb nse nsg nsn nso nsp nsr nss oaa oab oae oag oan oao oap oar oas ob- oba obb obe obg obn obo obp obr obs oea oeb oee oeg oen oeo oep oer oes oga oge ogg ogn ogo ogp ogs on- ona onb one ong onn ono onp onr ons oo- ooa oob oog oon ooo oop oor oos op- opa opb ope opg opn opo opp opr ops or- ora orb ore org orn oro orp orr ors os- osa osb ose osg osn oso osp osr oss p-p paa pab pae pag pan pao pap par pas pba pbb pbe pbg pbn pbo pbp pbr pbs pea peb pee peg pen peo pep per pes pga pgb pge pgg pgn pgo pgp pgr pgs pn- pna pnb pne png pnn pno pnp pnr pns poa pob poe pog pon poo pop por pos ppa ppb ppe ppg ppn ppo ppp ppr pps pra prb pre prg prn pro prp prr prs ps- psa psb pse psg psn pso psp psr pss ra- raa rab rae rag ran rao rap rar ras rba rbb rbe rbg rbn rbo rbp rbr rbs re- rea reb ree reg ren reo rep rer res rga rgb rge rgg rgn rgo rgp rgr rgs rna rnb rng rnn rno rnp rnr rns roa rob roe rog ron roo rop ror ros rpa rpb rpe rpg rpn rpo rpp rpr rps rra rrb rrg rrn rrp rrr rrs rsa rsb rse rsg rsn rso rsp rsr rss saa sab sae sag san sao sap sar sas sba sbb sbe sbg sbn sbo sbp sbr sbs se- sea seb see seg sen seo sep ser ses sga sgb sge sgg sgn sgo sgp sgr sgs sna snb sne sng snn sno snp snr sns soa sob soe sog son soo sop sor sos spa spb spe spg spn spo spp spr sps sr- sra srb sre srg srn sro srp srr srs ss- ssa ssb sse ssg ssn sso ssp ssr sss