bbb bbe bbf bbi bbo bbt bbx be- beb bee bef bei beo bet bex bfb bfe bff bfi bfo bft bfx bi- bib bie bif bii bio bit bix bob boe bof boi boo bot box btb bte btf bti bto btt btx bxb bxi bxo bxx ebb ebe ebf ebi ebo ebt ebx eeb eee eef eeo eet eex ef- efb efe eff efi efo eft efx eib eie eif eii eio eit eix eo- eob eoe eof eoi eoo eot etb ete etf eti eto ett etx ex- exe exi exo ext exx fbb fbe fbf fbi fbo fbt fbx feb fee fef fei feo fet fex ffe fff ffi ffo fft ffx fib fie fif fii fit fix fob foe fof foi foo fot fox ftb fte ftf fti fto ftt ftx fxe fxi fxt fxx i-f ibb ibe ibf ibi ibo ibt ibx ie- iee ief iei iet iex ifb ife iff ifi ifo ift ifx iib iie iif iii iio iit iix io- iob ioe iof ioi ioo iot itb ite itf iti ito itt itx ixe ixi o-i ob- obb obe obf obi obo obt obx oeb oee oef oei oeo oet oex of- ofb ofe off ofi ofo oft ofx oib oie oif oii oio oit oo- oob oof ooi ooo oot oox ot- otb ote otf oti oto ott ox- oxb oxf oxi oxo oxt oxx t-x tbb tbe tbf tbi tbo tbt te- teb tee tef tei teo tet tex tfb tfe tff tfi tfo tft tfx tib tie tif tii tio tit tix to- tob toe tof toi too tot tox ttb tte ttf tti tto ttt ttx txe txf txi txt xbe xbx xee xet xex xfe xft xfx xie xii xio xit xix xof xoi xoo xot xox xtf xti xtx xxi xxo xxx