a-a a-b aaa aab aag aao aar aas aau ab- aba abb abg abo abr abs abu ag- aga agb agg ago agr ags agu aoa aob aog aoo aor aos aou ar- ara arb arg aro arr ars aru as- asa asb asg aso asr ass asu au- aua aub aug auo aur aus b-u baa bab bag bao bar bas bau bba bbb bbg bbo bbr bbs bbu bga bgb bgg bgo bgr bgs bgu boa bob bog boo bor bos bou bra brb brg bro brr brs bru bsa bsb bsg bso bsr bss bsu bua bub bug buo bur bus buu gaa gab gag gao gar gas gau gba gbg gbo gbr gbs gbu gga ggb ggg ggo ggr ggs ggu goa gob gog goo gor gos gou gra grb grg gro grr grs gru gsa gsb gsg gso gsr gss gsu gu- gua gub gug guo gur gus guu oaa oab oag oao oar oas oau ob- oba obb obg obo obr obs obu oga ogg ogo ogs oo- ooa oob oog ooo oor oos or- ora orb org oro orr ors oru os- osa osb osg oso osr oss osu ou- oua ouo our ous ra- raa rab rag rao rar ras rau rba rbb rbg rbo rbr rbs rbu rga rgb rgg rgo rgr rgs roa rob rog roo ror ros rou rra rrb rrg rrr rrs rru rsa rsb rsg rso rsr rss rsu rua rub rug ruo rur rus ruu saa sab sag sao sar sas sau sba sbb sbg sbo sbr sbs sbu sga sgb sgg sgo sgr sgs sgu soa sob sog soo sor sos sou sr- sra srb srg sro srr srs ss- ssa ssb ssg sso ssr sss ssu sua sub sug suo sur sus suu ua- uaa uab uag uao uar uas uau uba ubb ubg ubo ubr ubs ubu uga ugb ugg ugo ugr ugs ugu uoa uob uog uoo uor uos ur- ura urb urg uro urr urs uru usa usb usg uso usr uss usu uua uug uur uus uuu