-ol bbb bbc bbd bbf bbk bbl bbo bcb bcc bcd bcf bck bcl bco bdb bdc bdd bdf bdk bdl bdo bfb bfc bfd bff bfl bfo bkb bkc bkf bkk bkl bko blb blc bld blf blk bll blo bob boc bod bof bok bol boo c-- cbb cbc cbd cbf cbk cbl cbo ccb ccc ccd ccf cck ccl cco cdb cdc cdd cdf cdk cdl cdo cfb cfc cfd cff cfk cfl cfo ckb ckc ckd cko cl- clb clc cld clf clk cll clo co- cob coc cod cof cok col coo dbb dbc dbd dbf dbk dbl dbo dcb dcc dcd dcf dck dcl dco ddb ddc ddd ddf ddk ddl ddo dfb dfc dfd dff dfk dfl dfo dkb dkc dkk dkl dko dl- dlb dlc dld dlf dlk dll dlo dob doc dod dof dok dol doo fbb fbc fbd fbf fbk fbl fbo fcb fcc fcd fcf fck fcl fco fdb fdc fdd fdf fdk fdl fdo ffc ffd fff ffk ffl ffo fkb fkc fkf fkk fkl flb flc fld flf fll flo fob foc fof fok fol foo kbb kbc kbd kbf kbk kbl kbo kcb kcc kcd kck kcl kdb kdc kdf kdk kdl kdo kfc kfd kff kfo kkb kkc kkk kkl kl- klb klc kld klf klo kob koc kod kof kok kol koo lbb lbc lbd lbf lbk lbl lbo lcb lcc lcd lcf lck lcl lco ldb ldc ldd ldf ldk ldl ldo lfb lfc lfd lff lfk lfl lfo lkb lkl llb llc lld llf llk lll llo lob loc lod lof lok lol loo ob- obb obc obd obf obk obl obo oc- ocb occ ocd ocf ock ocl oco odb odc odd odf odl odo of- ofb ofc ofd off ofl ofo okb okc okd okk okl oko olb olc old olf olk oll olo oo- oob ooc ood oof ook ool ooo