a-a a-b aaa aab aag aah aao aar aas ab- aba abb abg abh abo abr abs ag- aga agb agg agh ago agr ags aha ahb ahg ahh aho ahr ahs aoa aob aog aoh aoo aor aos ar- ara arb arg arh aro arr ars as- asa asb asg ash aso asr ass baa bab bag bah bao bar bas bba bbb bbg bbh bbo bbr bbs bga bgb bgg bgh bgo bgr bgs bha bhb bhg bhh bho bhr bhs boa bob bog boh boo bor bos bra brb brg brh bro brr brs bsa bsb bsg bsh bso bsr bss gaa gab gag gah gao gar gas gba gbg gbh gbo gbr gbs gga ggb ggg ggh ggo ggr ggs gha ghb ghg ghh gho ghr ghs goa gob gog goh goo gor gos gra grb grg grh gro grr grs gsa gsb gsg gso gsr gss haa hab hag hah hao har has hba hbb hbg hbh hbo hbr hbs hga hgb hgg hgh hgo hgr hgs hha hhb hhg hhh hho hhr hhs hoa hob hog hoh hoo hor hos hr- hra hrb hrg hrh hro hrr hrs hsa hsb hsg hsh hsr hss oaa oab oag oah oao oar oas ob- oba obb obg obh obo obr obs oga ogg ogh ogo ogs oha ohg ohh oho ohr ohs oo- ooa oob oog ooh ooo oor oos or- ora orb org orh oro orr ors os- osa osb osg osh oso osr oss ra- raa rab rag rah rao rar ras rba rbb rbg rbh rbo rbr rbs rga rgb rgg rgh rgo rgr rgs rh- rha rhb rhg rhh rho rhr rhs roa rob rog roh roo ror ros rra rrb rrg rrh rrr rrs rsa rsb rsg rsh rso rsr rss saa sab sag sah sao sar sas sba sbb sbg sbh sbo sbr sbs sga sgb sgg sgh sgo sgr sgs sh- sha shb shg shh sho shr shs soa sob sog soh soo sor sos sr- sra srb srg srh sro srr srs ss- ssa ssb ssg ssh sso ssr sss