-ic bbb bbc bbi bbo bbt bbx bby bcb bcc bci bco bct bcx bcy bi- bib bic bii bio bit bix biy bob boc boi boo bot box boy btb btc bti bto btt btx bty bxb bxi bxo bxx by- byc byi byo byt c-- cbb cbc cbi cbo cbt cbx cby ccb ccc cci cco cct ccx ci- cib cic cii cio cit cix co- cob coc coi coo cot cox coy ctb ctc cti cto ctt ctx cty cxc cxi cxo cxt cxx cyb cyc cyo cyt ibb ibc ibi ibo ibt ibx iby icb icc ici ico ict icy iib iic iii iio iit iix io- iob ioc ioi ioo iot itb itc iti ito itt itx ity ixc ixi ixy iyc iyo iyt iyy o-i ob- obb obc obi obo obt obx oby oc- ocb occ oci oco oct ocx oib oic oii oio oit oo- oob ooc ooi ooo oot oox ot- otb otc oti oto ott ox- oxb oxc oxi oxo oxt oxx oxy oyi oyo t-x tbb tbc tbi tbo tbt tcb tcc tci tco tct tcx tib tic tii tio tit tix tiy to- tob toc toi too tot tox toy ttb ttc tti tto ttt ttx tty txi txt tyc tyo tyt xbc xbx xcb xci xcx xic xii xio xit xix xoc xoi xoo xot xox xtc xti xtx xty xxi xxo xxx xxy xyy ybc ybi yby ycc yci yco ycy yii yio yit yob yoc yoi yoo yot yox yoy ytc yto ytt yxy yyb yyc yyt yyy