-er a-a a-b aaa aab aae aag aao aar aas aav ab- aba abb abe abg abo abr abs abv aea aeb aee aeg aeo aer aes aev ag- aga agb age agg ago agr ags agv aoa aob aoe aog aoo aor aos aov ar- ara arb are arg aro arr ars arv as- asa asb ase asg aso asr ass asv av- ava avb ave avg avo avr avs baa bab bae bag bao bar bas bav bba bbb bbe bbg bbo bbr bbs be- bea beb bee beg beo ber bes bev bga bgb bge bgg bgo bgr bgs bgv boa bob boe bog boo bor bos bov bra brb bre brg bro brr brs brv bsa bsb bse bsg bso bsr bss bsv bva bvb bve bvg bvo bvr bvs bvv eaa eab eae eag eao ear eas eav eba ebb ebe ebg ebo ebr ebs ebv eea eeb eee eeg eeo eer ees eev ega egb ege egg ego egr egs eo- eoa eob eoe eog eoo eor eos era erb ere erg ero err ers erv es- esa esb ese esg eso esr ess esv eva evb eve evg evo evr evs evv gaa gab gae gag gao gar gas gav gba gbe gbg gbo gbr gbs gbv ge- gea geb gee geg geo ger ges gev gga ggb ggg ggo ggr ggs ggv goa gob goe gog goo gor gos gov gra grb gre grg gro grr grs grv gsa gsb gse gsg gso gsr gss gsv gva gvb gve gvg gvo gvr gvs oaa oab oae oag oao oar oas oav ob- oba obb obe obg obo obr obs obv oea oeb oee oeg oeo oer oes oga oge ogg ogo ogs oo- ooa oob oog ooo oor oos oov or- ora orb ore org oro orr ors orv os- osa osb ose osg oso osr oss osv ov- ova ovb ove ovo ovs ovv ra- raa rab rae rag rao rar ras rav rba rbb rbe rbg rbo rbr rbs re- rea reb ree reg reo rer res rev rga rgb rge rgg rgo rgr rgs rgv roa rob roe rog roo ror ros rov rra rrb rrg rrr rrs rsa rsb rse rsg rso rsr rss rsv rva rvb rve rvg rvo rvr rvs rvv saa sab sae sag sao sar sas sav sba sbb sbe sbg sbo sbr sbs sbv se- sea seb see seg seo ser ses sev sga sgb sge sgg sgo sgr sgs sgv soa sob soe sog soo sor sos sov sr- sra srb sre srg sro srr srs srv ss- ssa ssb sse ssg sso ssr sss ssv sva svb sve svg svo svr svs svv v-a v-e vaa vab vae vag vao var vas vav vba vbg vbo vbr vbs vbv vea veb vee veg veo ver ves vga vgg vgo vgr vgs voa vob voe vog voo vor vos vov vra vrb vre vrg vrr vrs vsa vsb vse vsg vso vsr vss vsv vva vvb vvg vvo vvr vvs vvv