-ol bbb bbc bbl bbn bbo bbt bcb bcc bcl bcn bco bct blb blc bll bln blo blt bnb bnc bnl bnn bno bnt bob boc bol bon boo bot btb btc btl btn bto btt c-- cbb cbc cbl cbn cbo cbt ccb ccc ccl ccn cco cct cl- clb clc cll cln clo clt cn- cnb cnc cnl cnn cno cnt co- cob coc col con coo cot ctb ctc ctl ctn cto ctt lbb lbc lbl lbo lbt lcb lcc lcl lcn lco lct llb llc lll lln llo llt lnb lnc lnl lnn lno lnt lob loc lol lon loo lot ltb ltc ltl lto ltt nbb nbc nbl nbn nbo nbt ncb ncc ncl ncn nco nct nlb nlc nll nln nlo nlt nnb nnc nnl nnn nno nnt no- nob noc nol non noo not ntb ntc ntn nto ntt ob- obb obc obl obn obo obt oc- ocb occ ocl ocn oco oct olb olc oll oln olo olt on- onb onc onl onn ono ont oo- oob ooc ool oon ooo oot ot- otb otc otl otn oto ott tbb tbc tbl tbn tbo tbt tcb tcc tcl tcn tco tct tlc tll tln tlo tlt tnb tnc tnl tnn tno tnt to- tob toc tol ton too tot ttb ttc ttl ttn tto ttt