-ol bbb bbc bbd bbk bbl bbo bbs bcb bcc bcd bck bcl bco bcs bdb bdc bdd bdk bdl bdo bds bkb bkc bkk bkl bko bks blb blc bld blk bll blo bls bob boc bod bok bol boo bos bsb bsc bsd bsk bsl bso bss c-- cbb cbc cbd cbk cbl cbo cbs ccb ccc ccd cck ccl cco ccs cdb cdc cdd cdk cdl cdo cds ckb ckc ckd cko cks cl- clb clc cld clk cll clo cls co- cob coc cod cok col coo cos csb csc csd csk csl cso css dbb dbc dbd dbk dbl dbo dbs dcb dcc dcd dck dcl dco dcs ddb ddc ddd ddk ddl ddo dds dkb dkc dkk dkl dko dks dl- dlb dlc dld dlk dll dlo dls dob doc dod dok dol doo dos dsb dsc dsd dsk dsl dso dss kbb kbc kbd kbk kbl kbo kbs kcb kcc kcd kck kcl kcs kdb kdc kdk kdl kdo kds kkb kkc kkk kkl kks kl- klb klc kld klo kls kob koc kod kok kol koo kos ksb ksc ksd ksk ksl kso kss lbb lbc lbd lbk lbl lbo lbs lcb lcc lcd lck lcl lco lcs ldb ldc ldd ldk ldl ldo lds lkb lkl lks llb llc lld llk lll llo lls lob loc lod lok lol loo los lsb lsc lsd lsk lsl lso lss ob- obb obc obd obk obl obo obs oc- ocb occ ocd ock ocl oco ocs odb odc odd odl odo ods okb okc okd okk okl oko oks olb olc old olk oll olo ols oo- oob ooc ood ook ool ooo oos os- osb osc osd osk osl oso oss sbb sbc sbd sbk sbl sbo sbs scb scc scd sck scl sco scs sdb sdc sdd sdk sdl sdo sds sk- skb skc skd skk skl sko sks slb slc sld slk sll slo sls sob soc sod sok sol soo sos ss- ssb ssc ssd ssk ssl sso sss