bbb bbe bbl bbs bbt be- beb bee bel bes bet blb ble bll bls blt bsb bse bsl bss bst btb bte btl bts btt ebb ebe ebl ebs ebt eeb eee eel ees eet elb ele ell els elt es- esb ese esl ess est etb ete etl ets ett lbb lbe lbl lbs lbt leb lee lel les let llb lle lll lls llt lsb lse lsl lss lst ltb lte ltl lts ltt sbb sbe sbl sbs sbt se- seb see sel ses set slb sle sll sls slt ss- ssb sse ssl sss sst stb ste stl sts stt tbb tbe tbl tbs tbt te- teb tee tel tes tet tle tll tls tlt tsb tse tsl tss tst ttb tte ttl tts ttt