-er a-a a-b aaa aab aae aag aao aap aar aas ab- aba abb abe abg abo abp abr abs aea aeb aee aeg aeo aep aer aes ag- aga agb age agg ago agp agr ags aoa aob aoe aog aoo aop aor aos ap- apa apb ape apg apo app apr aps ar- ara arb are arg aro arp arr ars as- asa asb ase asg aso asp asr ass b-p baa bab bae bag bao bap bar bas bba bbb bbe bbg bbo bbp bbr bbs be- bea beb bee beg beo bep ber bes bga bgb bge bgg bgo bgp bgr bgs boa bob boe bog boo bop bor bos bpa bpb bpe bpg bpo bpp bpr bps bra brb bre brg bro brp brr brs bsa bsb bse bsg bso bsp bsr bss eaa eab eae eag eao eap ear eas eba ebb ebe ebg ebo ebp ebr ebs eea eeb eee eeg eeo eep eer ees ega egb ege egg ego egp egr egs eo- eoa eob eoe eog eoo eop eor eos ep- epa epb epe epg epo epp epr eps era erb ere erg ero erp err ers es- esa esb ese esg eso esp esr ess g-p gaa gab gae gag gao gap gar gas gba gbe gbg gbo gbp gbr gbs ge- gea geb gee geg geo gep ger ges gga ggb ggg ggo ggp ggr ggs goa gob goe gog goo gop gor gos gpa gpb gpe gpg gpo gpp gpr gps gra grb gre grg gro grp grr grs gsa gsb gse gsg gso gsp gsr gss oaa oab oae oag oao oap oar oas ob- oba obb obe obg obo obp obr obs oea oeb oee oeg oeo oep oer oes oga oge ogg ogo ogp ogs oo- ooa oob oog ooo oop oor oos op- opa opb ope opg opo opp opr ops or- ora orb ore org oro orp orr ors os- osa osb ose osg oso osp osr oss p-p paa pab pae pag pao pap par pas pba pbb pbe pbg pbo pbp pbr pbs pea peb pee peg peo pep per pes pga pgb pge pgg pgo pgp pgr pgs poa pob poe pog poo pop por pos ppa ppb ppe ppg ppo ppp ppr pps pra prb pre prg pro prp prr prs ps- psa psb pse psg pso psp psr pss ra- raa rab rae rag rao rap rar ras rba rbb rbe rbg rbo rbp rbr rbs re- rea reb ree reg reo rep rer res rga rgb rge rgg rgo rgp rgr rgs roa rob roe rog roo rop ror ros rpa rpb rpe rpg rpo rpp rpr rps rra rrb rrg rrp rrr rrs rsa rsb rse rsg rso rsp rsr rss saa sab sae sag sao sap sar sas sba sbb sbe sbg sbo sbp sbr sbs se- sea seb see seg seo sep ser ses sga sgb sge sgg sgo sgp sgr sgs soa sob soe sog soo sop sor sos spa spb spe spg spo spp spr sps sr- sra srb sre srg sro srp srr srs ss- ssa ssb sse ssg sso ssp ssr sss