a-a a-b aaa aab aag aah aar aas ab- aba abb abg abh abr abs ag- aga agb agg agh agr ags aha ahb ahg ahh ahr ahs ar- ara arb arg arh arr ars as- asa asb asg ash asr ass baa bab bag bah bar bas bba bbb bbg bbh bbr bbs bga bgb bgg bgh bgr bgs bha bhb bhg bhh bhr bhs bra brb brg brh brr brs bsa bsb bsg bsh bsr bss gaa gab gag gah gar gas gba gbg gbh gbr gbs gga ggb ggg ggh ggr ggs gha ghb ghg ghh ghr ghs gra grb grg grh grr grs gsa gsb gsg gsr gss haa hab hag hah har has hba hbb hbg hbh hbr hbs hga hgb hgg hgh hgr hgs hha hhb hhg hhh hhr hhs hr- hra hrb hrg hrh hrr hrs hsa hsb hsg hsh hsr hss ra- raa rab rag rah rar ras rba rbb rbg rbh rbr rbs rga rgb rgg rgh rgr rgs rh- rha rhb rhg rhh rhr rhs rra rrb rrg rrh rrr rrs rsa rsb rsg rsh rsr rss saa sab sag sah sar sas sba sbb sbg sbh sbr sbs sga sgb sgg sgh sgr sgs sh- sha shb shg shh shr shs sr- sra srb srg srh srr srs ss- ssa ssb ssg ssh ssr sss