-al -ol a-a a-b aaa aab aaf aal aan aao aar ab- aba abb abf abl abn abo abr af- afa afb aff afl afn afo afr al- ala alb alf all aln alo alr an- ana anb anf anl ann ano anr aoa aob aof aol aon aoo aor ar- ara arb arf arl arn aro arr baa bab baf bal ban bao bar bba bbb bbf bbl bbn bbo bbr bfa bfb bff bfl bfn bfo bfr bla blb blf bll bln blo blr bna bnb bnf bnl bnn bno bnr boa bob bof bol bon boo bor bra brb brf brl brn bro brr faa fab faf fal fan fao far fba fbb fbf fbl fbn fbo fbr ffa fff ffl ffn ffo ffr fla flb flf fll fln flo flr fna fnb fnf fnl fnn fnr foa fob fof fol fon foo for fra frb frf frl frn fro frr la- laa lab laf lal lan lao lar lba lbb lbf lbl lbo lbr lfa lfb lff lfl lfn lfo lfr lla llb llf lll lln llo llr lna lnb lnl lnn lno lnr loa lob lof lol lon loo lor lra lrb lrf lrn lro lrr naa nab naf nal nan nao nar nba nbb nbf nbl nbn nbo nbr nfa nfb nff nfl nfn nfo nfr nla nlb nlf nll nln nlo nlr nna nnb nnf nnl nnn nno no- noa nob nof nol non noo nor nra nrb nrf nrl nrn nro nrr oaa oab oaf oal oan oao oar ob- oba obb obf obl obn obo obr of- ofa ofb off ofl ofn ofo ofr ola olb olf oll oln olo on- ona onb onf onl onn ono onr oo- ooa oob oof ool oon ooo oor or- ora orb orf orl orn oro orr ra- raa rab raf ral ran rao rar rba rbb rbf rbl rbn rbo rbr rfa rfb rff rfl rfn rfo rfr rla rlf rll rln rlo rlr rna rnb rnn rno rnr roa rob rof rol ron roo ror rra rrb rrf rrl rrn rrr