-ic bbb bbc bbi bbo bbt bbx bcb bcc bci bco bct bcx bi- bib bic bii bio bit bix bob boc boi boo bot box btb btc bti bto btt btx bxb bxi bxo bxx c-- cbb cbc cbi cbo cbt cbx ccb ccc cci cco cct ccx ci- cib cic cii cio cit cix co- cob coc coi coo cot cox ctb ctc cti cto ctt ctx cxc cxi cxo cxt cxx ibb ibc ibi ibo ibt ibx icb icc ici ico ict iib iic iii iio iit iix io- iob ioc ioi ioo iot itb itc iti ito itt itx ixc ixi o-i ob- obb obc obi obo obt obx 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 t-x tbb tbc tbi tbo tbt tcb tcc tci tco tct tcx tib tic tii tio tit tix to- tob toc toi too tot tox ttb ttc tti tto ttt ttx txi txt xbc xbx xcb xci xcx xic xii xio xit xix xoc xoi xoo xot xox xtc xti xtx xxi xxo xxx