bbb bbc bbe bbl bbt bcb bcc bce bcl bct be- beb bec bee bel bet blb blc ble bll blt btb btc bte btl btt c-- cbb cbc cbe cbl cbt ccb ccc cce ccl cct ce- ceb cec cee cel cet cl- clb clc cle cll clt ctb ctc cte ctl ctt ebb ebc ebe ebl ebt ec- ecb ecc ece ecl ect eeb eec eee eel eet elb elc ele ell elt etb etc ete etl ett lbb lbc lbe lbl lbt lcb lcc lce lcl lct leb lec lee lel let llb llc lle lll llt ltb ltc lte ltl ltt tbb tbc tbe tbl tbt tcb tcc tce tcl tct te- teb tec tee tel tet tlc tle tll tlt ttb ttc tte ttl ttt