-ol bbb bbc bbk bbl bbn bbo bbr bcb bcc bck bcl bcn bco bcr bkb bkc bkk bkl bkn bko bkr blb blc blk bll bln blo blr bnb bnc bnk bnl bnn bno bnr bob boc bok bol bon boo bor brb brk brl brn bro brr c-- cbb cbc cbk cbl cbn cbo cbr ccb ccc cck ccl ccn cco ccr ckb ckc cko cl- clb clc clk cll cln clo clr cn- cnb cnc cnl cnn cno cnr co- cob coc cok col con coo cor crb crc crk crl crn cro crr kbb kbc kbk kbl kbn kbo kbr kcb kcc kck kcl kcn kcr kkb kkc kkk kkl kkn kkr kl- klb klc klo klr kn- knc knk knl knn kno knr kob koc kok kol kon koo kor krc krk krl krn kro krr lbb lbc lbk lbl lbo lbr lcb lcc lck lcl lcn lco lcr lkb lkl lkr llb llc llk lll lln llo llr lnb lnc lnk lnl lnn lno lnr lob loc lok lol lon loo lor lrb lrc lrk lrn lro lrr nbb nbc nbk nbl nbn nbo nbr ncb ncc nck ncl ncn nco ncr nkc nkk nkn nko nkr nlb nlc nlk nll nln nlo nlr nnb nnc nnk nnl nnn nno no- nob noc nok nol non noo nor nrb nrc nrk nrl nrn nro nrr ob- obb obc obk obl obn obo obr oc- ocb occ ock ocl ocn oco ocr okb okc okk okl oko okr olb olc olk oll oln olo on- onb onc onk onl onn ono onr oo- oob ooc ook ool oon ooo oor or- orb orc ork orl orn oro orr rbb rbc rbk rbl rbn rbo rbr rcb rcc rcl rcn rco rcr rkb rkc rkk rko rlc rll rln rlo rlr rnb rnc rnn rno rnr rob roc rok rol ron roo ror rrb rrc rrk rrl rrn rrr