a-a a-b a-z aaa aab aaf aag aan aar aau aaz ab- aba abb abf abg abn abr abu abz af- afa afb aff afg afn afr afu afz ag- aga agb agf agg agn agr agu agz an- ana anb anf ang ann anr anu anz ar- ara arb arf arg arn arr aru arz au- aua aub auf aug aun aur auz az- aza azb azf azg azn azu azz b-u baa bab baf bag ban bar bau baz bba bbb bbf bbg bbn bbr bbu bfa bfb bff bfg bfn bfr bfu bfz bga bgb bgf bgg bgn bgr bgu bgz bna bnb bnf bng bnn bnr bnu bnz bra brb brf brg brn brr bru brz bua bub buf bug bun bur buu buz bza bzf bzn bzr bzu bzz faa fab faf fag fan far fau faz fba fbb fbf fbg fbn fbr fbu ffa fff ffg ffn ffr ffu ffz fga fgb fgf fgg fgn fgr fgz fna fnb fnf fng fnn fnr fnu fnz fra frb frf frg frn frr fru fua fub fuf fug fun fur fuu gaa gab gaf gag gan gar gau gaz gba gbf gbg gbn gbr gbu gbz gfa gfb gff gfr gfz gga ggb ggg ggn ggr ggu ggz gna gnb gnf gnn gnr gnu gra grb grf grg grn grr gru gu- gua gub guf gug gun gur guu guz gza gzr gzu naa nab naf nag nan nar nau naz nba nbb nbf nbg nbn nbr nbu nfa nfb nff nfn nfr nfu nga ngb ngf ngg ngn ngu nna nnb nnf nng nnn nnu nnz nra nrb nrf nrg nrn nrr nru nrz nua nub nug nun nur nuu nzb nzf nzg nzz ra- raa rab raf rag ran rar rau raz rba rbb rbf rbg rbn rbr rbu rfa rfb rff rfg rfn rfr rfu rfz rga rgb rgf rgg rgn rgr rna rnb rng rnn rnr rnu rnz rra rrb rrf rrg rrn rrr rru rua rub ruf rug run rur ruu ruz rza rzb ua- uaa uab uaf uag uan uar uau uaz uba ubb ubf ubg ubn ubr ubu ufa uff ufg ufn ufr ufu uga ugb ugf ugg ugn ugr ugu un- una unb unf ung unn unr unu ur- ura urb urf urg urn urr uru urz uua uug uun uur uuu uza uzb uzu z-g zaa zab zaf zag zan zar zaz zbb zbr zfa zfn zfr zgb zgg znn zub zug zun zur zuz zzr zzz