-al -ol a-a a-b aaa aab aad aaf aak aal aao ab- aba abb abd abf abk abl abo ad- ada adb add adf adk adl ado af- afa afb afd aff afk afl afo aka akb akd akk akl ako al- ala alb ald alf alk all alo aoa aob aod aof aok aol aoo baa bab bad baf bak bal bao bba bbb bbd bbf bbk bbl bbo bda bdb bdd bdf bdk bdl bdo bfa bfb bfd bff bfl bfo bka bkb bkf bkk bkl bko bla blb bld blf blk bll blo boa bob bod bof bok bol boo daa dab dad daf dak dal dao dba dbb dbd dbf dbk dbl dbo dda ddb ddd ddf ddk ddl ddo dfa dfb dfd dff dfk dfl dfo dka dkb dkk dkl dko dl- dla dlb dld dlf dlk dll dlo doa dob dod dof dok dol doo faa fab fad faf fak fal fao fba fbb fbd fbf fbk fbl fbo fda fdb fdd fdf fdk fdl fdo ffa ffd fff ffk ffl ffo fka fkb fkf fkk fkl fla flb fld flf fll flo foa fob fof fok fol foo ka- kaa kab kad kaf kak kal kao kba kbb kbd kbf kbk kbl kbo kda kdb kdf kdk kdl kdo kfa kfd kff kfo kkb kkk kkl kl- kla klb kld klf klo koa kob kod kof kok kol koo la- laa lab lad laf lak lal lao lba lbb lbd lbf lbk lbl lbo lda ldb ldd ldf ldk ldl ldo lfa lfb lfd lff lfk lfl lfo lka lkb lkl lla llb lld llf llk lll llo loa lob lod lof lok lol loo oaa oab oad oaf oak oal oao ob- oba obb obd obf obk obl obo oda odb odd odf odl odo of- ofa ofb ofd off ofl ofo oka okb okd okk okl oko ola olb old olf olk oll olo oo- ooa oob ood oof ook ool ooo