bbb bbc bbe bbl bbs bbt bcb bcc bce bcl bcs bct be- beb bec bee bel bes bet blb blc ble bll bls blt bsb bsc bse bsl bss bst btb btc bte btl bts btt c-- cbb cbc cbe cbl cbs cbt ccb ccc cce ccl ccs cct ce- ceb cec cee cel ces cet cl- clb clc cle cll cls clt csb csc cse csl css cst ctb ctc cte ctl cts ctt ebb ebc ebe ebl ebs ebt ec- ecb ecc ece ecl ecs ect eeb eec eee eel ees eet elb elc ele ell els elt es- esb esc ese esl ess est etb etc ete etl ets ett lbb lbc lbe lbl lbs lbt lcb lcc lce lcl lcs lct leb lec lee lel les let llb llc lle lll lls llt lsb lsc lse lsl lss lst ltb ltc lte ltl lts ltt sbb sbc sbe sbl sbs sbt scb scc sce scl scs sct se- seb sec see sel ses set slb slc sle sll sls slt ss- ssb ssc sse ssl sss sst stb stc ste stl sts stt tbb tbc tbe tbl tbs tbt tcb tcc tce tcl tcs tct te- teb tec tee tel tes tet tlc tle tll tls tlt tsb tsc tse tsl tss tst ttb ttc tte ttl tts ttt