bbb bbc bbe bbo bbt bbx bcb bcc bce bco bct bcx be- beb bec bee beo bet bex bob boc boe boo bot box btb btc bte bto btt btx bxb bxo bxx c-- cbb cbc cbe cbo cbt cbx ccb ccc cce cco cct ccx ce- ceb cec cee ceo cet cex co- cob coc coe coo cot cox ctb ctc cte cto ctt ctx cxc cxo cxt cxx ebb ebc ebe ebo ebt ebx ec- ecb ecc ece eco ect ecx eeb eec eee eeo eet eex eo- eob eoc eoe eoo eot etb etc ete eto ett etx ex- exc exe exo ext exx ob- obb obc obe obo obt obx oc- ocb occ oco oct ocx oeb oec oee oeo oet oex oo- oob ooc ooo oot oox ot- otb otc ote oto ott ox- oxb oxc oxo oxt oxx t-x tbb tbc tbe tbo tbt tcb tcc tce tco tct tcx te- teb tec tee teo tet tex to- tob toc toe too tot tox ttb ttc tte tto ttt ttx txe txt xbc xbe xbx xcb xcx xee xet xex xoc xoo xot xox xtc xtx xxo xxx