-al -ol a-a a-b aaa aab aaf aal aan aao ab- aba abb abf abl abn abo af- afa afb aff afl afn afo al- ala alb alf all aln alo an- ana anb anf anl ann ano aoa aob aof aol aon aoo baa bab baf bal ban bao bba bbb bbf bbl bbn bbo bfa bfb bff bfl bfn bfo bla blb blf bll bln blo bna bnb bnf bnl bnn bno boa bob bof bol bon boo faa fab faf fal fan fao fba fbb fbf fbl fbn fbo ffa fff ffl ffn ffo fla flb flf fll fln flo fna fnb fnf fnl fnn foa fob fof fol fon foo la- laa lab laf lal lan lao lba lbb lbf lbl lbo lfa lfb lff lfl lfn lfo lla llb llf lll lln llo lna lnb lnl lnn lno loa lob lof lol lon loo naa nab naf nal nan nao nba nbb nbf nbl nbn nbo nfa nfb nff nfl nfn nfo nla nlb nlf nll nln nlo nna nnb nnf nnl nnn nno no- noa nob nof nol non noo oaa oab oaf oal oan oao ob- oba obb obf obl obn obo of- ofa ofb off ofl ofn ofo ola olb olf oll oln olo on- ona onb onf onl onn ono oo- ooa oob oof ool oon ooo