a-a a-b a-t aaa aab aan aao aat aax ab- aba abb abn abo abt abx an- ana anb ann ano ant anx aoa aob aon aoo aot aox at- ata atb atn ato att atx ax- axa axn axo axt axx baa bab ban bao bat bax bba bbb bbn bbo bbt bbx bna bnb bnn bno bnt bnx boa bob bon boo bot box bta btb btn bto btt btx bxb bxn bxo bxx naa nab nan nao nat nax nba nbb nbn nbo nbt nbx nna nnb nnn nno nnt no- noa nob non noo not nox nta ntb ntn nto ntt ntx nxt oaa oab oan oao oat oax ob- oba obb obn obo obt obx on- ona onb onn ono ont onx oo- ooa oob oon ooo oot oox ot- ota otb otn oto ott ox- oxa oxb oxn oxo oxt oxx t-x taa tab tan tao tat tax tba tbb tbn tbo tbt tna tnb tnn tno tnt tnx to- toa tob ton too tot tox tta ttb ttn tto ttt ttx txn txt xaa xan xat xbx xna xno xoa xon xoo xot xox xtx xxo xxx