a-a a-b aaa aab aaf aag aah aan aao aar ab- aba abb abf abg abh abn abo abr af- afa afb aff afg afh afn afo afr ag- aga agb agf agg agh agn ago agr aha ahb ahf ahg ahh ahn aho ahr an- ana anb anf ang anh ann ano anr aoa aob aof aog aoh aon aoo aor ar- ara arb arf arg arh arn aro arr baa bab baf bag bah ban bao bar bba bbb bbf bbg bbh bbn bbo bbr bfa bfb bff bfg bfh bfn bfo bfr bga bgb bgf bgg bgh bgn bgo bgr bha bhb bhf bhg bhh bho bhr bna bnb bnf bng bnn bno bnr boa bob bof bog boh bon boo bor bra brb brf brg brh brn bro brr faa fab faf fag fah fan fao far fba fbb fbf fbg fbh fbn fbo fbr ffa fff ffg ffh ffn ffo ffr fga fgb fgf fgg fgh fgn fgr fha fhb fhf fhg fhh fhn fho fhr fna fnb fnf fng fnh fnn fnr foa fob fof fog foh fon foo for fra frb frf frg frh frn fro frr gaa gab gaf gag gah gan gao gar gba gbf gbg gbh gbn gbo gbr gfa gfb gff gfh gfo gfr gga ggb ggg ggh ggn ggo ggr gha ghb ghg ghh ghn gho ghr gna gnb gnf gnn gno gnr goa gob gof gog goh gon goo gor gra grb grf grg grh grn gro grr haa hab haf hag hah han hao har hba hbb hbf hbg hbh hbn hbo hbr hfa hfb hff hfg hfh hfn hfo hfr hga hgb hgf hgg hgh hgn hgo hgr hha hhb hhf hhg hhh hhn hho hhr hna hnb hnf hng hnh hnn hno hoa hob hof hog hoh hon hoo hor hr- hra hrb hrf hrg hrh hrn hro hrr naa nab naf nag nah nan nao nar nba nbb nbf nbg nbn nbo nbr nfa nfb nff nfn nfo nfr nga ngb ngf ngg ngh ngn ngo nha nhb nhf nhg nhh nhn nhr nna nnb nnf nng nnh nnn nno no- noa nob nof nog noh non noo nor nra nrb nrf nrg nrn nro nrr oaa oab oaf oag oah oan oao oar ob- oba obb obf obg obh obn obo obr of- ofa ofb off ofg ofn ofo ofr oga ogf ogg ogh ogn ogo oha ohf ohg ohh ohn oho ohr on- ona onb onf ong onh onn ono onr oo- ooa oob oof oog ooh oon ooo oor or- ora orb orf org orh orn oro orr ra- raa rab raf rag rah ran rao rar rba rbb rbf rbg rbh rbn rbo rbr rfa rfb rff rfg rfh rfn rfo rfr rga rgb rgf rgg rgh rgn rgo rgr rh- rha rhb rhf rhg rhh rhn rho rhr rna rnb rng rnh rnn rno rnr roa rob rof rog roh ron roo ror rra rrb rrf rrg rrh rrn rrr