-al -ol a-a a-b a-c a-t aaa aab aac aae aak aal aao aat ab- aba abb abc abe abk abl abo abt ac- aca acb acc ace ack acl aco act aea aeb aec aee aek ael aeo aet aka akb akc ake akk akl ako al- ala alb alc ale alk all alo alt aoa aob aoc aoe aok aol aoo aot at- ata atb atc ate atl ato att baa bab bac bae bak bal bao bat bba bbb bbc bbe bbk bbl bbo bbt bca bcb bcc bce bck bcl bco bct be- bea beb bec bee bek bel beo bet bka bkb bkc bke bkk bkl bko bkt bla blb blc ble blk bll blo blt boa bob boc boe bok bol boo bot bta btb btc bte btk btl bto btt c-- caa cab cac cae cak cal cao cat cba cbb cbc cbe cbk cbl cbo cbt cca ccb ccc cce cck ccl cco cct ce- cea ceb cec cee cek cel ceo cet cka ckb ckc cko ckt cl- cla clb clc cle clk cll clo clt co- coa cob coc coe cok col coo cot cta ctb ctc cte ctk ctl cto ctt eaa eab eac eae eak eal eao eat eba ebb ebc ebe ebk ebl ebo ebt ec- eca ecb ecc ece eck ecl eco ect eea eeb eec eee eek eel eeo eet eka ekb ekc eke ekl eko ekt ela elb elc ele elk ell elo elt eo- eoa eob eoc eoe eok eol eoo eot eta etb etc ete etk etl eto ett k-t ka- kaa kab kac kae kak kal kao kat kba kbb kbc kbe kbk kbl kbo kca kcb kcc kce kck kcl kct ke- kea keb kec kee kek kel keo ket kkb kkc kke kkk kkl kkt kl- kla klb klc klo klt koa kob koc koe kok kol koo kot kta ktb ktc kte ktk ktl kto ktt la- laa lab lac lae lak lal lao lat lba lbb lbc lbe lbk lbl lbo lbt lca lcb lcc lce lck lcl lco lct lea leb lec lee lek lel leo let lka lkb lkl lkt lla llb llc lle llk lll llo llt loa lob loc loe lok lol loo lot lta ltb ltc lte ltk ltl lto ltt oaa oab oac oae oak oal oao oat ob- oba obb obc obe obk obl obo obt oc- oca ocb occ ock ocl oco oct oea oeb oec oee oel oeo oet oka okb okc oke okk okl oko ola olb olc ole olk oll olo olt oo- ooa oob ooc ook ool ooo oot ot- ota otb otc ote otk otl oto ott taa tab tac tae tak tal tao tat tba tbb tbc tbe tbk tbl tbo tbt tca tcb tcc tce tck tcl tco tct te- tea teb tec tee tek tel teo tet tka tkb tkc tke tkk tkl tko tkt tla tlc tle tlk tll tlo tlt to- toa tob toc toe tok tol too tot tta ttb ttc tte ttk ttl tto ttt