a-a a-b a-i aaa aab aag aai aak aao aar ab- aba abb abg abi abk abo abr ag- aga agb agg agi agk ago agr ai- aia aib aig aii aik aio air aka akb akg aki akk ako akr aoa aob aog aoi aok aoo aor ar- ara arb arg ari ark aro arr baa bab bag bai bak bao bar bba bbb bbg bbi bbk bbo bbr bga bgb bgg bgi bgk bgo bgr bi- bia bib big bii bik bio bir bka bkb bkg bkk bko bkr boa bob bog boi bok boo bor bra brb brg bri brk bro brr gaa gab gag gai gak gao gar gba gbg gbi gbk gbo gbr gga ggb ggg ggi ggo ggr gia gib gig gii gik gio gir gka gkb gko goa gob gog goi gok goo gor gra grb grg gri grk gro grr ia- iaa iab iag iai iao iar iba ibb ibg ibi ibk ibo ibr iga igb igg igi igk igo igr iia iib iii iio iir ika ikb iki ikk iko ikr io- ioa iob iog ioi ioo ior ir- ira irb irg iri irk iro irr ka- kaa kab kag kai kak kao kar kba kbb kbi kbk kbo kbr kga kgb kgi kgo kia kib kig kii kik kio kir kkb kki kkk kkr koa kob kog koi kok koo kor kra krg kri krk kro krr o-i oaa oab oag oai oak oao oar ob- oba obb obg obi obk obo obr oga ogg ogi ogo oia oib oii oik oio oir oka okb okg oki okk oko okr oo- ooa oob oog ooi ook ooo oor or- ora orb org ori ork oro orr ra- raa rab rag rai rak rao rar rba rbb rbg rbi rbk rbo rbr rga rgb rgg rgi rgk rgo rgr ria rib rig rii rik rio rir rkb rkg rkk rko roa rob rog roi rok roo ror rra rrb rrg rri rrk rrr