-er -ol bbb bbc bbe bbk bbl bbo bbr bcb bcc bce bck bcl bco bcr bcz be- beb bec bee bek bel beo ber bez bkb bkc bke bkk bkl bko bkr blb blc ble blk bll blo blr blz bob boc boe bok bol boo bor boz brb bre brk brl bro brr brz bze bzo bzr bzz c-- cbb cbc cbe cbk cbl cbo cbr cbz ccb ccc cce cck ccl cco ccr ccz ce- ceb cec cee cek cel ceo cer cez ckb ckc cko cl- clb clc cle clk cll clo clr clz co- cob coc coe cok col coo cor coz crb crc cre crk crl cro crr crz cz- czc cze czk czo ebb ebc ebe ebk ebl ebo ebr ec- ecb ecc ece eck ecl eco ecr eeb eec eee eek eel eeo eer ekb ekc eke ekl eko ekr elb elc ele elk ell elo elr elz eo- eob eoc eoe eok eol eoo eor erb erc ere erk erl ero err erz eze ezo ezr ezz k-z kbb kbc kbe kbk kbl kbo kbr kbz kcb kcc kce kck kcl kcr ke- keb kec kee kek kel keo ker kez kkb kkc kke kkk kkl kkr kl- klb klc klo klr klz kob koc koe kok kol koo kor koz krc krk krl kro krr kzo lbb lbc lbe lbk lbl lbo lbr lcb lcc lce lck lcl lco lcr leb lec lee lek lel leo ler lez lkb lkl lkr llb llc lle llk lll llo llr llz lob loc loe lok lol loo lor loz lrb lrc lrk lro lrr lrz lzo lzr ob- obb obc obe obk obl obo obr oc- ocb occ ock ocl oco ocr ocz oeb oec oee oel oeo oer okb okc oke okk okl oko okr olb olc ole olk oll olo oo- oob ooc ook ool ooo oor or- orb orc ore ork orl oro orr orz oze ozo ozz rbb rbc rbe rbk rbl rbo rbr rcb rcc rce rcl rco rcr re- reb rec ree rek rel reo rer rez rkb rkc rke rkk rko rkz rlc rle rll rlo rlr rob roc roe rok rol roo ror roz rrb rrc rrk rrl rrr rzb rze rzo zbb zbc zbl zbr zce zcl zco zeb zec zee zek zel zeo zer zez zlr zo- zob zoc zoe zok zol zoo zor zrl zro zzr zzz