-al -ol a-a a-b a-c a-t aaa aab aac aak aal aan aao aat ab- aba abb abc abk abl abn abo abt ac- aca acb acc ack acl acn aco act aka akb akc akk akl akn ako al- ala alb alc alk all aln alo alt an- ana anb anc ank anl ann ano ant aoa aob aoc aok aol aon aoo aot at- ata atb atc atl atn ato att baa bab bac bak bal ban bao bat bba bbb bbc bbk bbl bbn bbo bbt bca bcb bcc bck bcl bcn bco bct bka bkb bkc bkk bkl bkn bko bkt bla blb blc blk bll bln blo blt bna bnb bnc bnk bnl bnn bno bnt boa bob boc bok bol bon boo bot bta btb btc btk btl btn bto btt c-- caa cab cac cak cal can cao cat cba cbb cbc cbk cbl cbn cbo cbt cca ccb ccc cck ccl ccn cco cct cka ckb ckc cko ckt cl- cla clb clc clk cll cln clo clt cn- cna cnb cnc cnl cnn cno cnt co- coa cob coc cok col con coo cot cta ctb ctc ctk ctl ctn cto ctt k-t ka- kaa kab kac kak kal kan kao kat kba kbb kbc kbk kbl kbn kbo kca kcb kcc kck kcl kcn kct kkb kkc kkk kkl kkn kkt kl- kla klb klc klo klt kn- kna knc knk knl knn kno knt koa kob koc kok kol kon koo kot kta ktb ktc ktk ktl ktn kto ktt la- laa lab lac lak lal lan lao lat lba lbb lbc lbk lbl lbo lbt lca lcb lcc lck lcl lcn lco lct lka lkb lkl lkt lla llb llc llk lll lln llo llt lna lnb lnc lnk lnl lnn lno lnt loa lob loc lok lol lon loo lot lta ltb ltc ltk ltl lto ltt naa nab nac nak nal nan nao nat nba nbb nbc nbk nbl nbn nbo nbt nca ncb ncc nck ncl ncn nco nct nka nkc nkk nkn nko nkt nla nlb nlc nlk nll nln nlo nlt nna nnb nnc nnk nnl nnn nno nnt no- noa nob noc nok nol non noo not nta ntb ntc ntk ntn nto ntt oaa oab oac oak oal oan oao oat ob- oba obb obc obk obl obn obo obt oc- oca ocb occ ock ocl ocn oco oct oka okb okc okk okl oko ola olb olc olk oll oln olo olt on- ona onb onc onk onl onn ono ont oo- ooa oob ooc ook ool oon ooo oot ot- ota otb otc otk otl otn oto ott taa tab tac tak tal tan tao tat tba tbb tbc tbk tbl tbn tbo tbt tca tcb tcc tck tcl tcn tco tct tka tkb tkc tkk tkl tko tkt tla tlc tlk tll tln tlo tlt tna tnb tnc tnk tnl tnn tno tnt to- toa tob toc tok tol ton too tot tta ttb ttc ttk ttl ttn tto ttt