-ic bbb bbc bbe bbi bbo bbt bcb bcc bce bci bco bct be- beb bec bee bei beo bet bi- bib bic bie bii bio bit bob boc boe boi boo bot btb btc bte bti bto btt c-- cbb cbc cbe cbi cbo cbt ccb ccc cce cci cco cct ce- ceb cec cee cei ceo cet ci- cib cic cie cii cio cit co- cob coc coe coi coo cot ctb ctc cte cti cto ctt ebb ebc ebe ebi ebo ebt ec- ecb ecc ece eci eco ect eeb eec eee eeo eet eib eic eie eii eio eit eo- eob eoc eoe eoi eoo eot etb etc ete eti eto ett ibb ibc ibe ibi ibo ibt icb icc ice ici ico ict ie- iec iee iei iet iib iic iie iii iio iit io- iob ioc ioe ioi ioo iot itb itc ite iti ito itt o-i ob- obb obc obe obi obo obt oc- ocb occ oci oco oct oeb oec oee oei oeo oet oib oic oie oii oio oit oo- oob ooc ooi ooo oot ot- otb otc ote oti oto ott tbb tbc tbe tbi tbo tbt tcb tcc tce tci tco tct te- teb tec tee tei teo tet tib tic tie tii tio tit to- tob toc toe toi too tot ttb ttc tte tti tto ttt