-ol bbb bbc bbd bbk bbl bbo bbt bcb bcc bcd bck bcl bco bct bdb bdc bdd bdk bdl bdo bdt bkb bkc bkk bkl bko bkt blb blc bld blk bll blo blt bob boc bod bok bol boo bot btb btc btd btk btl bto btt c-- cbb cbc cbd cbk cbl cbo cbt ccb ccc ccd cck ccl cco cct cdb cdc cdd cdk cdl cdo cdt ckb ckc ckd cko ckt cl- clb clc cld clk cll clo clt co- cob coc cod cok col coo cot ctb ctc ctd ctk ctl cto ctt dbb dbc dbd dbk dbl dbo dbt dcb dcc dcd dck dcl dco dct ddb ddc ddd ddk ddl ddo ddt dkb dkc dkk dkl dko dkt dl- dlb dlc dld dlk dll dlo dlt dob doc dod dok dol doo dot dtb dtc dtd dtk dtl dto dtt k-t kbb kbc kbd kbk kbl kbo kcb kcc kcd kck kcl kct kdb kdc kdk kdl kdo kdt kkb kkc kkk kkl kkt kl- klb klc kld klo klt kob koc kod kok kol koo kot ktb ktc ktk ktl kto ktt lbb lbc lbd lbk lbl lbo lbt lcb lcc lcd lck lcl lco lct ldb ldc ldd ldk ldl ldo ldt lkb lkl lkt llb llc lld llk lll llo llt lob loc lod lok lol loo lot ltb ltc ltd ltk ltl lto ltt ob- obb obc obd obk obl obo obt oc- ocb occ ocd ock ocl oco oct odb odc odd odl odo odt okb okc okd okk okl oko olb olc old olk oll olo olt oo- oob ooc ood ook ool ooo oot ot- otb otc otd otk otl oto ott tbb tbc tbd tbk tbl tbo tbt tcb tcc tcd tck tcl tco tct tdb tdc tdd tdk tdl tdo tdt tkb tkc tkk tkl tko tkt tlc tld tlk tll tlo tlt to- tob toc tod tok tol too tot ttb ttc ttd ttk ttl tto ttt