a-a a-b a-t aaa aab aag aan aas aat ab- aba abb abg abn abs abt ag- aga agb agg agn ags agt an- ana anb ang ann ans ant as- asa asb asg asn ass ast at- ata atb atg atn ats att baa bab bag ban bas bat bba bbb bbg bbn bbs bbt bga bgb bgg bgn bgs bgt bna bnb bng bnn bns bnt bsa bsb bsg bsn bss bst bta btb btg btn bts btt gaa gab gag gan gas gat gba gbg gbn gbs gbt gga ggb ggg ggn ggs ggt gna gnb gnn gns gnt gsa gsb gsg gsn gss gst gta gtb gtg gtn gts gtt naa nab nag nan nas nat nba nbb nbg nbn nbs nbt nga ngb ngg ngn ngs ngt nna nnb nng nnn nns nnt nsa nsb nsg nsn nss nst nta ntb ntg ntn nts ntt saa sab sag san sas sat sba sbb sbg sbn sbs sbt sga sgb sgg sgn sgs sgt sna snb sng snn sns snt ss- ssa ssb ssg ssn sss sst sta stb stg stn sts stt taa tab tag tan tas tat tba tbb tbg tbn tbs tbt tga tgb tgg tgn tgs tgt tna tnb tng tnn tns tnt tsa tsb tsg tsn tss tst tta ttb ttg ttn tts ttt