a-a a-b a-i aaa aab aag aai aan aao aar ab- aba abb abg abi abn abo abr ag- aga agb agg agi agn ago agr ai- aia aib aig aii ain aio air an- ana anb ang ani ann ano anr aoa aob aog aoi aon aoo aor ar- ara arb arg ari arn aro arr baa bab bag bai ban bao bar bba bbb bbg bbi bbn bbo bbr bga bgb bgg bgi bgn bgo bgr bi- bia bib big bii bin bio bir bna bnb bng bni bnn bno bnr boa bob bog boi bon boo bor bra brb brg bri brn bro brr gaa gab gag gai gan gao gar gba gbg gbi gbn gbo gbr gga ggb ggg ggi ggn ggo ggr gia gib gig gii gin gio gir gna gnb gni gnn gno gnr goa gob gog goi gon goo gor gra grb grg gri grn gro grr ia- iaa iab iag iai ian iao iar iba ibb ibg ibi ibn ibo ibr iga igb igg igi ign igo igr iia iib iii iin iio iir in- ina inb ing ini inn ino inr io- ioa iob iog ioi ion ioo ior ir- ira irb irg iri irn iro irr n-i naa nab nag nai nan nao nar nba nbb nbg nbi nbn nbo nbr nga ngb ngg ngi ngn ngo nia nib nig nii nin nio nir nna nnb nng nni nnn nno no- noa nob nog noi non noo nor nra nrb nrg nri nrn nro nrr o-i oaa oab oag oai oan oao oar ob- oba obb obg obi obn obo obr oga ogg ogi ogn ogo oia oib oii oin oio oir on- ona onb ong oni onn ono onr oo- ooa oob oog ooi oon ooo oor or- ora orb org ori orn oro orr ra- raa rab rag rai ran rao rar rba rbb rbg rbi rbn rbo rbr rga rgb rgg rgi rgn rgo rgr ria rib rig rii rin rio rir rna rnb rng rni rnn rno rnr roa rob rog roi ron roo ror rra rrb rrg rri rrn rrr