a-a a-c a-t aaa aac aad aas aat ac- aca acc acd acs act ad- ada adc add ads adt as- asa asc asd ass ast at- ata atc atd ats att c-- caa cac cad cas cat cca ccc ccd ccs cct cda cdc cdd cds cdt csa csc csd css cst cta ctc ctd cts ctt daa dac dad das dat dca dcc dcd dcs dct dda ddc ddd dds ddt dsa dsc dsd dss dst dta dtc dtd dts dtt saa sac sad sas sat sca scc scd scs sct sda sdc sdd sds sdt ss- ssa ssc ssd sss sst sta stc std sts stt taa tac tad tas tat tca tcc tcd tcs tct tda tdc tdd tds tdt tsa tsc tsd tss tst tta ttc ttd tts ttt