-ol bbb bbd bbk bbl bbo bdb bdd bdk bdl bdo bkb bkk bkl bko blb bld blk bll blo bob bod bok bol boo dbb dbd dbk dbl dbo ddb ddd ddk ddl ddo dkb dkk dkl dko dl- dlb dld dlk dll dlo dob dod dok dol doo kbb kbd kbk kbl kbo kdb kdk kdl kdo kkb kkk kkl kl- klb kld klo kob kod kok kol koo lbb lbd lbk lbl lbo ldb ldd ldk ldl ldo lkb lkl llb lld llk lll llo lob lod lok lol loo ob- obb obd obk obl obo odb odd odl odo okb okd okk okl oko olb old olk oll olo oo- oob ood ook ool ooo