-er -ol bbb bbc bbe bbl bbo bbr bbs bcb bcc bce bcl bco bcr bcs be- beb bec bee bel beo ber bes blb blc ble bll blo blr bls bob boc boe bol boo bor bos brb bre brl bro brr brs bsb bsc bse bsl bso bsr bss c-- cbb cbc cbe cbl cbo cbr cbs ccb ccc cce ccl cco ccr ccs ce- ceb cec cee cel ceo cer ces cl- clb clc cle cll clo clr cls co- cob coc coe col coo cor cos crb crc cre crl cro crr crs csb csc cse csl cso csr css ebb ebc ebe ebl ebo ebr ebs ec- ecb ecc ece ecl eco ecr ecs eeb eec eee eel eeo eer ees elb elc ele ell elo elr els eo- eob eoc eoe eol eoo eor eos erb erc ere erl ero err ers es- esb esc ese esl eso esr ess lbb lbc lbe lbl lbo lbr lbs lcb lcc lce lcl lco lcr lcs leb lec lee lel leo ler les llb llc lle lll llo llr lls lob loc loe lol loo lor los lrb lrc lro lrr lrs lsb lsc lse lsl lso lsr lss ob- obb obc obe obl obo obr obs oc- ocb occ ocl oco ocr ocs oeb oec oee oel oeo oer oes olb olc ole oll olo ols oo- oob ooc ool ooo oor oos or- orb orc ore orl oro orr ors os- osb osc ose osl oso osr oss rbb rbc rbe rbl rbo rbr rbs rcb rcc rce rcl rco rcr rcs re- reb rec ree rel reo rer res rlc rle rll rlo rlr rls rob roc roe rol roo ror ros rrb rrc rrl rrr rrs rsb rsc rse rsl rso rsr rss sbb sbc sbe sbl sbo sbr sbs scb scc sce scl sco scr scs se- seb sec see sel seo ser ses slb slc sle sll slo slr sls sob soc soe sol soo sor sos sr- srb src sre srl sro srr srs ss- ssb ssc sse ssl sso ssr sss