-al -ol a-a a-b a-t aaa aab aad aaf aal aao aat ab- aba abb abd abf abl abo abt ad- ada adb add adf adl ado adt af- afa afb afd aff afl afo aft al- ala alb ald alf all alo alt aoa aob aod aof aol aoo aot at- ata atb atd atf atl ato att baa bab bad baf bal bao bat bba bbb bbd bbf bbl bbo bbt bda bdb bdd bdf bdl bdo bdt bfa bfb bfd bff bfl bfo bft bla blb bld blf bll blo blt boa bob bod bof bol boo bot bta btb btd btf btl bto btt daa dab dad daf dal dao dat dba dbb dbd dbf dbl dbo dbt dda ddb ddd ddf ddl ddo ddt dfa dfb dfd dff dfl dfo dft dl- dla dlb dld dlf dll dlo dlt doa dob dod dof dol doo dot dta dtb dtd dtf dtl dto dtt faa fab fad faf fal fao fat fba fbb fbd fbf fbl fbo fbt fda fdb fdd fdf fdl fdo fdt ffa ffd fff ffl ffo fft fla flb fld flf fll flo flt foa fob fof fol foo fot fta ftb ftd ftf ftl fto ftt la- laa lab lad laf lal lao lat lba lbb lbd lbf lbl lbo lbt lda ldb ldd ldf ldl ldo ldt lfa lfb lfd lff lfl lfo lft lla llb lld llf lll llo llt loa lob lod lof lol loo lot lta ltb ltd ltf ltl lto ltt oaa oab oad oaf oal oao oat ob- oba obb obd obf obl obo obt oda odb odd odf odl odo odt of- ofa ofb ofd off ofl ofo oft ola olb old olf oll olo olt oo- ooa oob ood oof ool ooo oot ot- ota otb otd otf otl oto ott taa tab tad taf tal tao tat tba tbb tbd tbf tbl tbo tbt tda tdb tdd tdf tdl tdo tdt tfa tfb tfd tff tfl tfo tft tla tld tlf tll tlo tlt to- toa tob tod tof tol too tot tta ttb ttd ttf ttl tto ttt