a-a a-b a-i aaa aab aag aai aan aar ab- aba abb abg abi abn abr ag- aga agb agg agi agn agr ai- aia aib aig aii ain air an- ana anb ang ani ann anr ar- ara arb arg ari arn arr baa bab bag bai ban bar bba bbb bbg bbi bbn bbr bga bgb bgg bgi bgn bgr bi- bia bib big bii bin bir bna bnb bng bni bnn bnr bra brb brg bri brn brr gaa gab gag gai gan gar gba gbg gbi gbn gbr gga ggb ggg ggi ggn ggr gia gib gig gii gin gir gna gnb gni gnn gnr gra grb grg gri grn grr ia- iaa iab iag iai ian iar iba ibb ibg ibi ibn ibr iga igb igg igi ign igr iia iib iii iin iir in- ina inb ing ini inn inr ir- ira irb irg iri irn irr n-i naa nab nag nai nan nar nba nbb nbg nbi nbn nbr nga ngb ngg ngi ngn nia nib nig nii nin nir nna nnb nng nni nnn nra nrb nrg nri nrn nrr ra- raa rab rag rai ran rar rba rbb rbg rbi rbn rbr rga rgb rgg rgi rgn rgr ria rib rig rii rin rir rna rnb rng rni rnn rnr rra rrb rrg rri rrn rrr