a-a a-c a-t aaa aac aao aas aat aax aay ac- aca acc aco acs act acx acy aoa aoc aoo aos aot aox as- asa asc aso ass ast asx asy at- ata atc ato ats att atx ax- axa axo axs axt axx ay- aya ayc ayo ays ayt ayx c-- caa cac cao cas cat cax cay cca ccc cco ccs cct ccx co- coa coc coo cos cot cox coy csa csc cso css cst csx csy cta ctc cto cts ctt ctx cty cxc cxo cxs cxt cxx cya cyc cyo cys cyt oaa oac oao oas oat oax oc- oca occ oco ocs oct ocx oo- ooa ooc ooo oos oot oox os- osa osc oso oss ost osx ot- ota otc oto ots ott ox- oxa oxc oxo oxt oxx oxy oya oyo oys saa sac sao sas sat sax say sca scc sco scs sct scx soa soc soo sos sot sox soy ss- ssa ssc sso sss sst ssx sta stc sto sts stt stx sty sxc sxs sxt sy- sya syc sys syt syx t-x taa tac tao tas tat tax tay tca tcc tco tcs tct tcx to- toa toc too tos tot tox toy tsa tsc tso tss tst tsx tsy tta ttc tto tts ttt ttx tty txs txt tya tyc tyo tys tyt xaa xac xas xat xcx xoa xoc xoo xos xot xox xsa xsc xss xst xtc xts xtx xty xxo xxx xxy xyy yaa yac yao yas yat yax yay yca ycc yco ycs ycy yoc yoo yos yot yox yoy ysa ysc yso yss yst ysy yta ytc yto yts ytt yxa yxy yyc yys yyt yyy