a-a a-t aaa aag aas aat aax ag- aga agg ags agt agx as- asa asg ass ast asx at- ata atg ats att atx ax- axa axs axt axx gaa gag gas gat gga ggg ggs ggt gsa gsg gss gst gsx gta gtg gts gtt gtx gxa gxs gxt saa sag sas sat sax sga sgg sgs sgt sgx ss- ssa ssg sss sst ssx sta stg sts stt stx sxs sxt t-x taa tag tas tat tax tga tgg tgs tgt tsa tsg tss tst tsx tta ttg tts ttt ttx txs txt xaa xag xas xat xsa xss xst xts xtx xxx