bbb bbc bbe bbl bbs bcb bcc bce bcl bcs be- beb bec bee bel bes blb blc ble bll bls bsb bsc bse bsl bss c-- cbb cbc cbe cbl cbs ccb ccc cce ccl ccs ce- ceb cec cee cel ces cl- clb clc cle cll cls csb csc cse csl css ebb ebc ebe ebl ebs ec- ecb ecc ece ecl ecs eeb eec eee eel ees elb elc ele ell els es- esb esc ese esl ess lbb lbc lbe lbl lbs lcb lcc lce lcl lcs leb lec lee lel les llb llc lle lll lls lsb lsc lse lsl lss sbb sbc sbe sbl sbs scb scc sce scl scs se- seb sec see sel ses slb slc sle sll sls ss- ssb ssc sse ssl sss