-al -ol a-a a-b a-c aaa aab aac aad aak aal aao ab- aba abb abc abd abk abl abo ac- aca acb acc acd ack acl aco ad- ada adb adc add adk adl ado aka akb akc akd akk akl ako al- ala alb alc ald alk all alo aoa aob aoc aod aok aol aoo baa bab bac bad bak bal bao bba bbb bbc bbd bbk bbl bbo bca bcb bcc bcd bck bcl bco bda bdb bdc bdd bdk bdl bdo bka bkb bkc bkk bkl bko bla blb blc bld blk bll blo boa bob boc bod bok bol boo c-- caa cab cac cad cak cal cao cba cbb cbc cbd cbk cbl cbo cca ccb ccc ccd cck ccl cco cda cdb cdc cdd cdk cdl cdo cka ckb ckc ckd cko cl- cla clb clc cld clk cll clo co- coa cob coc cod cok col coo daa dab dac dad dak dal dao dba dbb dbc dbd dbk dbl dbo dca dcb dcc dcd dck dcl dco dda ddb ddc ddd ddk ddl ddo dka dkb dkc dkk dkl dko dl- dla dlb dlc dld dlk dll dlo doa dob doc dod dok dol doo ka- kaa kab kac kad kak kal kao kba kbb kbc kbd kbk kbl kbo kca kcb kcc kcd kck kcl kda kdb kdc kdk kdl kdo kkb kkc kkk kkl kl- kla klb klc kld klo koa kob koc kod kok kol koo la- laa lab lac lad lak lal lao lba lbb lbc lbd lbk lbl lbo lca lcb lcc lcd lck lcl lco lda ldb ldc ldd ldk ldl ldo lka lkb lkl lla llb llc lld llk lll llo loa lob loc lod lok lol loo oaa oab oac oad oak oal oao ob- oba obb obc obd obk obl obo oc- oca ocb occ ocd ock ocl oco oda odb odc odd odl odo oka okb okc okd okk okl oko ola olb olc old olk oll olo oo- ooa oob ooc ood ook ool ooo