-er -ol bbb bbc bbe bbl bbo bbr bbt bcb bcc bce bcl bco bcr bct be- beb bec bee bel beo ber bet blb blc ble bll blo blr blt bob boc boe bol boo bor bot brb bre brl bro brr brt btb btc bte btl bto btr btt c-- cbb cbc cbe cbl cbo cbr cbt ccb ccc cce ccl cco ccr cct ce- ceb cec cee cel ceo cer cet cl- clb clc cle cll clo clr clt co- cob coc coe col coo cor cot crb crc cre crl cro crr crt ctb ctc cte ctl cto ctr ctt ebb ebc ebe ebl ebo ebr ebt ec- ecb ecc ece ecl eco ecr ect eeb eec eee eel eeo eer eet elb elc ele ell elo elr elt eo- eob eoc eoe eol eoo eor eot erb erc ere erl ero err ert etb etc ete etl eto etr ett lbb lbc lbe lbl lbo lbr lbt lcb lcc lce lcl lco lcr lct leb lec lee lel leo ler let llb llc lle lll llo llr llt lob loc loe lol loo lor lot lrb lrc lro lrr lrt ltb ltc lte ltl lto ltr ltt ob- obb obc obe obl obo obr obt oc- ocb occ ocl oco ocr oct oeb oec oee oel oeo oer oet olb olc ole oll olo olt oo- oob ooc ool ooo oor oot or- orb orc ore orl oro orr ort ot- otb otc ote otl oto otr ott rbb rbc rbe rbl rbo rbr rbt rcb rcc rce rcl rco rcr rct re- reb rec ree rel reo rer ret rlc rle rll rlo rlr rlt rob roc roe rol roo ror rot rrb rrc rrl rrr rrt rtb rtc rte rtl rto rtr rtt tbb tbc tbe tbl tbo tbr tbt tcb tcc tce tcl tco tcr tct te- teb tec tee tel teo ter tet tlc tle tll tlo tlr tlt to- tob toc toe tol too tor tot trb trc tre trl tro trr trt ttb ttc tte ttl tto ttr ttt