a-a a-c a-t aaa aac aao aat aax ac- aca acc aco act acx aoa aoc aoo aot aox at- ata atc ato att atx ax- axa axo axt axx c-- caa cac cao cat cax cca ccc cco cct ccx co- coa coc coo cot cox cta ctc cto ctt ctx cxc cxo cxt cxx oaa oac oao oat oax oc- oca occ oco oct ocx oo- ooa ooc ooo oot oox ot- ota otc oto ott ox- oxa oxc oxo oxt oxx t-x taa tac tao tat tax tca tcc tco tct tcx to- toa toc too tot tox tta ttc tto ttt ttx txt xaa xac xat xcx xoa xoc xoo xot xox xtc xtx xxo xxx