-ic bbb bbc bbe bbi bbo bbt bbx bcb bcc bce bci bco bct bcx be- beb bec bee bei beo bet bex bi- bib bic bie bii bio bit bix bob boc boe boi boo bot box btb btc bte bti bto btt btx bxb bxi bxo bxx c-- cbb cbc cbe cbi cbo cbt cbx ccb ccc cce cci cco cct ccx ce- ceb cec cee cei ceo cet cex ci- cib cic cie cii cio cit cix co- cob coc coe coi coo cot cox ctb ctc cte cti cto ctt ctx cxc cxi cxo cxt cxx ebb ebc ebe ebi ebo ebt ebx ec- ecb ecc ece eci eco ect ecx eeb eec eee eeo eet eex eib eic eie eii eio eit eix eo- eob eoc eoe eoi eoo eot etb etc ete eti eto ett etx ex- exc exe exi exo ext exx ibb ibc ibe ibi ibo ibt ibx icb icc ice ici ico ict ie- iec iee iei iet iex iib iic iie iii iio iit iix io- iob ioc ioe ioi ioo iot itb itc ite iti ito itt itx ixc ixe ixi o-i ob- obb obc obe obi obo obt obx oc- ocb occ oci oco oct ocx oeb oec oee oei oeo oet oex oib oic oie oii oio oit oo- oob ooc ooi ooo oot oox ot- otb otc ote oti oto ott ox- oxb oxc oxi oxo oxt oxx t-x tbb tbc tbe tbi tbo tbt tcb tcc tce tci tco tct tcx te- teb tec tee tei teo tet tex tib tic tie tii tio tit tix to- tob toc toe toi too tot tox ttb ttc tte tti tto ttt ttx txe txi txt xbc xbe xbx xcb xci xcx xee xet xex xic xie xii xio xit xix xoc xoi xoo xot xox xtc xti xtx xxi xxo xxx