a-a a-b aaa aab aag aak aan aao aar ab- aba abb abg abk abn abo abr ag- aga agb agg agk agn ago agr aka akb akg akk akn ako akr an- ana anb ang ank ann ano anr aoa aob aog aok aon aoo aor ar- ara arb arg ark arn aro arr baa bab bag bak ban bao bar bba bbb bbg bbk bbn bbo bbr bga bgb bgg bgk bgn bgo bgr bka bkb bkg bkk bkn bko bkr bna bnb bng bnk bnn bno bnr boa bob bog bok bon boo bor bra brb brg brk brn bro brr gaa gab gag gak gan gao gar gba gbg gbk gbn gbo gbr gga ggb ggg ggn ggo ggr gka gkb gkn gko gna gnb gnn gno gnr goa gob gog gok gon goo gor gra grb grg grk grn gro grr ka- kaa kab kag kak kan kao kar kba kbb kbk kbn kbo kbr kga kgb kgo kkb kkk kkn kkr kn- kna kng knk knn kno knr koa kob kog kok kon koo kor kra krg krk krn kro krr naa nab nag nak nan nao nar nba nbb nbg nbk nbn nbo nbr nga ngb ngg ngk ngn ngo nka nkk nkn nko nkr nna nnb nng nnk nnn nno no- noa nob nog nok non noo nor nra nrb nrg nrk nrn nro nrr oaa oab oag oak oan oao oar ob- oba obb obg obk obn obo obr oga ogg ogn ogo oka okb okg okk oko okr on- ona onb ong onk onn ono onr oo- ooa oob oog ook oon ooo oor or- ora orb org ork orn oro orr ra- raa rab rag rak ran rao rar rba rbb rbg rbk rbn rbo rbr rga rgb rgg rgk rgn rgo rgr rkb rkg rkk rko rna rnb rng rnn rno rnr roa rob rog rok ron roo ror rra rrb rrg rrk rrn rrr