-ol bbb bbk bbl bbn bbo bbs bkb bkk bkl bkn bko bks blb blk bll bln blo bls bnb bnk bnl bnn bno bns bob bok bol bon boo bos bsb bsk bsl bsn bso bss kbb kbk kbl kbn kbo kbs kkb kkk kkl kkn kks kl- klb klo kls kn- knk knl knn kno kob kok kol kon koo kos ksb ksk ksl ksn kso kss lbb lbk lbl lbo lbs lkb lkl lks llb llk lll lln llo lls lnb lnk lnl lnn lno lns lob lok lol lon loo los lsb lsk lsl lsn lso lss nbb nbk nbl nbn nbo nbs nkk nkn nko nks nlb nlk nll nln nlo nls nnb nnk nnl nnn nno nns no- nob nok nol non noo nos nsb nsk nsl nsn nso nss ob- obb obk obl obn obo obs okb okk okl oko oks olb olk oll oln olo ols on- onb onk onl onn ono ons oo- oob ook ool oon ooo oos os- osb osk osl osn oso oss sbb sbk sbl sbn sbo sbs sk- skb skk skl sko sks slb slk sll sln slo sls snb snk snl snn sno sns sob sok sol son soo sos ss- ssb ssk ssl ssn sso sss