a-a a-c a-t aaa aac aae aan aao aat aax ac- aca acc ace acn aco act acx aea aec aee aen aeo aet aex an- ana anc ane ann ano ant anx aoa aoc aoe aon aoo aot aox at- ata atc ate atn ato att atx ax- axa axe axn axo axt axx c-- caa cac cae can cao cat cax cca ccc cce ccn cco cct ccx ce- cea cec cee cen ceo cet cex cn- cna cnc cne cnn cno cnt cnx co- coa coc coe con coo cot cox cta ctc cte ctn cto ctt ctx cxc cxo cxt cxx eaa eac eae ean eao eat eax ec- eca ecc ece ecn eco ect ecx eea eec eee een eeo eet eex en- ena enc ene enn eno ent eo- eoa eoc eoe eon eoo eot eta etc ete etn eto ett etx ex- exa exc exe exo ext exx naa nac nae nan nao nat nax nca ncc nce ncn nco nct ncx ne- nea nec nee nen neo net nex nna nnc nne nnn nno nnt no- noa noc noe non noo not nox nta ntc nte ntn nto ntt ntx nxc nxt oaa oac oae oan oao oat oax oc- oca occ ocn oco oct ocx oea oec oee oen oeo oet oex on- ona onc one onn ono ont onx oo- ooa ooc oon ooo oot oox ot- ota otc ote otn oto ott ox- oxa oxc oxn oxo oxt oxx t-x taa tac tae tan tao tat tax tca tcc tce tcn tco tct tcx te- tea tec tee ten teo tet tex tna tnc tne tnn tno tnt tnx to- toa toc toe ton too tot tox tta ttc tte ttn tto ttt ttx txe txn txt xaa xac xan xat xcx xee xen xet xex xna xnc xno xoa xoc xon xoo xot xox xtc xtx xxo xxx