a-a a-b aaa aab aak aam aao aar aau ab- aba abb abk abm abo abr abu aka akb akk akm ako akr aku ama amb amk amm amo amr amu aoa aob aok aom aoo aor aou ar- ara arb ark arm aro arr aru au- aua aub auk aum auo aur b-u baa bab bak bam bao bar bau bba bbb bbk bbm bbo bbr bbu bka bkb bkk bkm bko bkr bma bmb bmk bmm bmo bmr bmu boa bob bok bom boo bor bou bra brb brk brm bro brr bru bua bub buk bum buo bur buu ka- kaa kab kak kam kao kar kau kba kbb kbk kbm kbo kbr kbu kkb kkk kkm kkr kku kma kmb kmk kmm kmo kmu koa kob kok kom koo kor kou kra krk kro krr kru kub kuk kum kur kuu m-o m-r maa mab mak mam mao mar mau mba mbb mbk mbm mbo mbr mbu mka mkb mkk mkm mko mkr mku mma mmb mmk mmm mmo mmr mmu moa mob mok mom moo mor mou mra mrb mrk mrm mro mrr mru mua mub muk mum mur muu oaa oab oak oam oao oar oau ob- oba obb obk obm obo obr obu oka okb okk oko okr oku om- oma omb omm omo omr omu oo- ooa oob ook oom ooo oor or- ora orb ork orm oro orr oru ou- oua ouk oum ouo our ra- raa rab rak ram rao rar rau rba rbb rbk rbm rbo rbr rbu rkb rkk rkm rko rku rma rmb rmm rmo rmr roa rob rok rom roo ror rou rra rrb rrk rrm rrr rru rua rub ruk rum ruo rur ruu ua- uaa uab uak uam uao uar uau uba ubb ubk ubo ubr ubu uka ukb ukk ukr uku um- uma umb umm umo umr umu uoa uob uok uom uoo uor ur- ura urb urk urm uro urr uru uua uum uur uuu