a-a a-b aaa aab aag aak aao aar aau ab- aba abb abg abk abo abr abu ag- aga agb agg agk ago agr agu aka akb akg akk ako akr aku aoa aob aog aok aoo aor aou ar- ara arb arg ark aro arr aru au- aua aub aug auk auo aur b-u baa bab bag bak bao bar bau bba bbb bbg bbk bbo bbr bbu bga bgb bgg bgk bgo bgr bgu bka bkb bkg bkk bko bkr boa bob bog bok boo bor bou bra brb brg brk bro brr bru bua bub bug buk buo bur buu gaa gab gag gak gao gar gau gba gbg gbk gbo gbr gbu gga ggb ggg ggo ggr ggu gka gkb gko goa gob gog gok goo gor gou gra grb grg grk gro grr gru gu- gua gub gug guk guo gur guu ka- kaa kab kag kak kao kar kau kba kbb kbk kbo kbr kbu kga kgb kgo kgu kkb kkk kkr kku koa kob kog kok koo kor kou kra krg krk kro krr kru kub kug kuk kur kuu oaa oab oag oak oao oar oau ob- oba obb obg obk obo obr obu oga ogg ogo oka okb okg okk oko okr oku oo- ooa oob oog ook ooo oor or- ora orb org ork oro orr oru ou- oua ouk ouo our ra- raa rab rag rak rao rar rau rba rbb rbg rbk rbo rbr rbu rga rgb rgg rgk rgo rgr rkb rkg rkk rko rku roa rob rog rok roo ror rou rra rrb rrg rrk rrr rru rua rub rug ruk ruo rur ruu ua- uaa uab uag uak uao uar uau uba ubb ubg ubk ubo ubr ubu uga ugb ugg ugk ugo ugr ugu uka ukb ukk ukr uku uoa uob uog uok uoo uor ur- ura urb urg urk uro urr uru uua uug uur uuu