-er -ol bbb bbc bbe bbl bbo bbr bbt bcb bcc bce bcl bco bcr bct bcv be- beb bec bee bel beo ber bet bev blb blc ble bll blo blr blt blv bob boc boe bol boo bor bot bov brb bre brl bro brr brt brv btb btc bte btl bto btr btt btv bvb bvc bve bvl bvo bvr bvt bvv c-- cbb cbc cbe cbl cbo cbr cbt cbv ccb ccc cce ccl cco ccr cct ccv ce- ceb cec cee cel ceo cer cet cev cl- clb clc cle cll clo clr clt clv co- cob coc coe col coo cor cot cov crb crc cre crl cro crr crt crv ctb ctc cte ctl cto ctr ctt ctv cvb cvc cve cvl cvo cvr cvt cvv ebb ebc ebe ebl ebo ebr ebt ebv ec- ecb ecc ece ecl eco ecr ect ecv eeb eec eee eel eeo eer eet eev elb elc ele ell elo elr elt elv eo- eob eoc eoe eol eoo eor eot erb erc ere erl ero err ert erv etb etc ete etl eto etr ett etv evb evc eve evl evo evr evt evv lbb lbc lbe lbl lbo lbr lbt lbv lcb lcc lce lcl lco lcr lct lcv leb lec lee lel leo ler let lev llb llc lle lll llo llr llt llv lob loc loe lol loo lor lot lov lrb lrc lro lrr lrt lrv ltb ltc lte ltl lto ltr ltt ltv lvb lvc lve lvl lvr lvt lvv ob- obb obc obe obl obo obr obt obv oc- ocb occ ocl oco ocr oct ocv oeb oec oee oel oeo oer oet olb olc ole oll olo olt oo- oob ooc ool ooo oor oot oov or- orb orc ore orl oro orr ort orv ot- otb otc ote otl oto otr ott otv ov- ovb ovc ove ovl ovo ovv rbb rbc rbe rbl rbo rbr rbt rcb rcc rce rcl rco rcr rct rcv re- reb rec ree rel reo rer ret rev rlc rle rll rlo rlr rlt rob roc roe rol roo ror rot rov rrb rrc rrl rrr rrt rtb rtc rte rtl rto rtr rtt rtv rvb rvc rve rvl rvo rvr rvt rvv tbb tbc tbe tbl tbo tbr tbt tbv tcb tcc tce tcl tco tcr tct tcv te- teb tec tee tel teo ter tet tev tlc tle tll tlo tlr tlt tlv to- tob toc toe tol too tor tot tov trb trc tre trl tro trr trt trv ttb ttc tte ttl tto ttr ttt ttv tvb tvc tve tvl tvo tvr tvt v-e vbc vbl vbo vbr vbv vcc vce vcl vco vcr vct veb vec vee vel veo ver vet vl- vlb vlc vle vll vlo vlt vlv vob voc voe vol voo vor vot vov vrb vrc vre vrr vrt vtb vtc vte vtl vto vtr vtt vtv vvb vvc vvo vvr vvt vvv