a-a a-b a-c aaa aab aac aag aan aar aau ab- aba abb abc abg abn abr abu ac- aca acb acc acg acn acr acu ag- aga agb agc agg agn agr agu an- ana anb anc ang ann anr anu ar- ara arb arc arg arn arr aru au- aua aub auc aug aun aur b-u baa bab bac bag ban bar bau bba bbb bbc bbg bbn bbr bbu bca bcb bcc bcg bcn bcr bcu bga bgb bgc bgg bgn bgr bgu bna bnb bnc bng bnn bnr bnu bra brb brg brn brr bru bua bub buc bug bun bur buu c-- caa cab cac cag can car cau cba cbb cbc cbg cbn cbr cbu cca ccb ccc ccg ccn ccr ccu cga cgb cgc cgg cgn cgr cgu cn- cna cnb cnc cng cnn cnr cnu cra crb crc crg crn crr cru cua cub cuc cug cun cur cuu gaa gab gac gag gan gar gau gba gbc gbg gbn gbr gbu gca gcb gcc gcg gcn gcr gcu gga ggb ggc ggg ggn ggr ggu gna gnb gnc gnn gnr gnu gra grb grc grg grn grr gru gu- gua gub guc gug gun gur guu naa nab nac nag nan nar nau nba nbb nbc nbg nbn nbr nbu nca ncb ncc ncg ncn ncr ncu nga ngb ngc ngg ngn ngu nna nnb nnc nng nnn nnu nra nrb nrc nrg nrn nrr nru nua nub nuc nug nun nur nuu ra- raa rab rac rag ran rar rau rba rbb rbc rbg rbn rbr rbu rca rcb rcc rcg rcn rcr rcu rga rgb rgc rgg rgn rgr rna rnb rnc rng rnn rnr rnu rra rrb rrc rrg rrn rrr rru rua rub ruc rug run rur ruu ua- uaa uab uac uag uan uar uau uba ubb ubc ubg ubn ubr ubu uca ucb ucc ucg ucn ucr ucu uga ugb ugc ugg ugn ugr ugu un- una unb unc ung unn unr unu ur- ura urb urc urg urn urr uru uua uuc uug uun uur uuu