a-a a-b a-c aaa aab aac aag aau ab- aba abb abc abg abu ac- aca acb acc acg acu ag- aga agb agc agg agu au- aua aub auc aug b-u baa bab bac bag bau bba bbb bbc bbg bbu bca bcb bcc bcg bcu bga bgb bgc bgg bgu bua bub buc bug buu c-- caa cab cac cag cau cba cbb cbc cbg cbu cca ccb ccc ccg ccu cga cgb cgc cgg cgu cua cub cuc cug cuu gaa gab gac gag gau gba gbc gbg gbu gca gcb gcc gcg gcu gga ggb ggc ggg ggu gu- gua gub guc gug guu ua- uaa uab uac uag uau uba ubb ubc ubg ubu uca ucb ucc ucg ucu uga ugb ugc ugg ugu uua uuc uug uuu