-ol bbb bbc bbl bbn bbo bcb bcc bcl bcn bco blb blc bll bln blo bnb bnc bnl bnn bno bob boc bol bon boo c-- cbb cbc cbl cbn cbo ccb ccc ccl ccn cco cl- clb clc cll cln clo cn- cnb cnc cnl cnn cno co- cob coc col con coo lbb lbc lbl lbo lcb lcc lcl lcn lco llb llc lll lln llo lnb lnc lnl lnn lno lob loc lol lon loo nbb nbc nbl nbn nbo ncb ncc ncl ncn nco nlb nlc nll nln nlo nnb nnc nnl nnn nno no- nob noc nol non noo ob- obb obc obl obn obo oc- ocb occ ocl ocn oco olb olc oll oln olo on- onb onc onl onn ono oo- oob ooc ool oon ooo