-al -ol a-a a-b a-c a-t aaa aab aac aaf aal aao aat ab- aba abb abc abf abl abo abt ac- aca acb acc acf acl aco act af- afa afb afc aff afl afo aft al- ala alb alc alf all alo alt aoa aob aoc aof aol aoo aot at- ata atb atc atf atl ato att baa bab bac baf bal bao bat bba bbb bbc bbf bbl bbo bbt bca bcb bcc bcf bcl bco bct bfa bfb bfc bff bfl bfo bft bla blb blc blf bll blo blt boa bob boc bof bol boo bot bta btb btc btf btl bto btt c-- caa cab cac caf cal cao cat cba cbb cbc cbf cbl cbo cbt cca ccb ccc ccf ccl cco cct cfa cfb cfc cff cfl cfo cft cl- cla clb clc clf cll clo clt co- coa cob coc cof col coo cot cta ctb ctc ctf ctl cto ctt faa fab fac faf fal fao fat fba fbb fbc fbf fbl fbo fbt fca fcb fcc fcf fcl fco fct ffa ffc fff ffl ffo fft fla flb flc flf fll flo flt foa fob foc fof fol foo fot fta ftb ftc ftf ftl fto ftt la- laa lab lac laf lal lao lat lba lbb lbc lbf lbl lbo lbt lca lcb lcc lcf lcl lco lct lfa lfb lfc lff lfl lfo lft lla llb llc llf lll llo llt loa lob loc lof lol loo lot lta ltb ltc ltf ltl lto ltt oaa oab oac oaf oal oao oat ob- oba obb obc obf obl obo obt oc- oca ocb occ ocf ocl oco oct of- ofa ofb ofc off ofl ofo oft ola olb olc olf oll olo olt oo- ooa oob ooc oof ool ooo oot ot- ota otb otc otf otl oto ott taa tab tac taf tal tao tat tba tbb tbc tbf tbl tbo tbt tca tcb tcc tcf tcl tco tct tfa tfb tfc tff tfl tfo tft tla tlc tlf tll tlo tlt to- toa tob toc tof tol too tot tta ttb ttc ttf ttl tto ttt