a-a a-b a-c aaa aab aac aag aan aau ab- aba abb abc abg abn abu ac- aca acb acc acg acn acu ag- aga agb agc agg agn agu an- ana anb anc ang ann anu au- aua aub auc aug aun b-u baa bab bac bag ban bau bba bbb bbc bbg bbn bbu bca bcb bcc bcg bcn bcu bga bgb bgc bgg bgn bgu bna bnb bnc bng bnn bnu bua bub buc bug bun buu c-- caa cab cac cag can cau cba cbb cbc cbg cbn cbu cca ccb ccc ccg ccn ccu cga cgb cgc cgg cgn cgu cn- cna cnb cnc cng cnn cnu cua cub cuc cug cun cuu gaa gab gac gag gan gau gba gbc gbg gbn gbu gca gcb gcc gcg gcn gcu gga ggb ggc ggg ggn ggu gna gnb gnc gnn gnu gu- gua gub guc gug gun guu naa nab nac nag nan nau nba nbb nbc nbg nbn nbu nca ncb ncc ncg ncn ncu nga ngb ngc ngg ngn ngu nna nnb nnc nng nnn nnu nua nub nuc nug nun nuu ua- uaa uab uac uag uan uau uba ubb ubc ubg ubn ubu uca ucb ucc ucg ucn ucu uga ugb ugc ugg ugn ugu un- una unb unc ung unn unu uua uuc uug uun uuu