-ey bbb bbe bbi bbt bbx bby be- beb bee bei bet bex bey bi- bib bie bii bit bix biy btb bte bti btt btx bty bxb bxi bxx by- bye byi byt ebb ebe ebi ebt ebx eby eeb eee eet eex eey eib eie eii eit eix etb ete eti ett etx ety ex- exe exi ext exx exy eye eyt ibb ibe ibi ibt ibx iby ie- iee iei iet iex iey iib iie iii iit iix itb ite iti itt itx ity ixe ixi ixy iye iyt iyy t-x tbb tbe tbi tbt te- teb tee tei tet tex tey tib tie tii tit tix tiy ttb tte tti ttt ttx tty txe txi txt tye tyt xbe xbx xee xet xex xie xii xit xix xti xtx xty xxi xxx xxy xyy ybe ybi yby yeb yee yei yet yex yey yie yii yit yte ytt yxe yxy yyb yye yyt yyy