a-a a-b a-i a-t aaa aab aai aao aat aax aay ab- aba abb abi abo abt abx aby ai- aia aib aii aio ait aix aiy aoa aob aoi aoo aot aox at- ata atb ati ato att atx ax- axa axi axo axt axx ay- aya ayi ayo ayt ayx baa bab bai bao bat bax bay bba bbb bbi bbo bbt bbx bby bi- bia bib bii bio bit bix biy boa bob boi boo bot box boy bta btb bti bto btt btx bty bxb bxi bxo bxx by- bya byi byo byt ia- iaa iab iai iao iat iba ibb ibi ibo ibt ibx iby iia iib iii iio iit iix io- ioa iob ioi ioo iot ita itb iti ito itt itx ity ixi ixy iya iyo iyt iyy o-i oaa oab oai oao oat oax ob- oba obb obi obo obt obx oby oia oib oii oio oit oo- ooa oob ooi ooo oot oox ot- ota otb oti oto ott ox- oxa oxb oxi oxo oxt oxx oxy oya oyi oyo t-x taa tab tai tao tat tax tay tba tbb tbi tbo tbt tia tib tii tio tit tix tiy to- toa tob toi too tot tox toy tta ttb tti tto ttt ttx tty txi txt tya tyo tyt xaa xat xbx xia xii xio xit xix xoa xoi xoo xot xox xti xtx xty xxi xxo xxx xxy xyy yaa yab yai yao yat yax yay ybi yby yii yio yit yob yoi yoo yot yox yoy yta yto ytt yxa yxy yyb yyt yyy