-ic a-a a-b a-c a-i a-t aaa aab aac aag aai aas aat ab- aba abb abc abg abi abs abt ac- aca acb acc acg aci acs act ag- aga agb agc agg agi ags agt ai- aia aib aic aig aii ais ait as- asa asb asc asg asi ass ast at- ata atb atc atg ati ats att baa bab bac bag bai bas bat bba bbb bbc bbg bbi bbs bbt bca bcb bcc bcg bci bcs bct bga bgb bgc bgg bgi bgs bgt bi- bia bib bic big bii bis bit bsa bsb bsc bsg bsi bss bst bta btb btc btg bti bts btt c-- caa cab cac cag cai cas cat cba cbb cbc cbg cbi cbs cbt cca ccb ccc ccg cci ccs cct cga cgb cgc cgg cgi cgs cgt ci- cia cib cic cig cii cis cit csa csb csc csg csi css cst cta ctb ctc ctg cti cts ctt gaa gab gac gag gai gas gat gba gbc gbg gbi gbs gbt gca gcb gcc gcg gci gcs gct gga ggb ggc ggg ggi ggs ggt gia gib gic gig gii gis git gsa gsb gsc gsg gsi gss gst gta gtb gtc gtg gti gts gtt ia- iaa iab iac iag iai ias iat iba ibb ibc ibg ibi ibs ibt ica icb icc icg ici ics ict iga igb igc igg igi igs igt iia iib iic iii iis iit is- isa isb isc isg isi iss ist ita itb itc itg iti its itt saa sab sac sag sai sas sat sba sbb sbc sbg sbi sbs sbt sca scb scc scg sci scs sct sga sgb sgc sgg sgi sgs sgt sia sib sic sig sii sis sit ss- ssa ssb ssc ssg ssi sss sst sta stb stc stg sti sts stt taa tab tac tag tai tas tat tba tbb tbc tbg tbi tbs tbt tca tcb tcc tcg tci tcs tct tga tgb tgc tgg tgi tgs tgt tia tib tic tig tii tis tit tsa tsb tsc tsg tsi tss tst tta ttb ttc ttg tti tts ttt