a-a a-b a-c a-t aaa aab aac aae aak aao aat ab- aba abb abc abe abk abo abt ac- aca acb acc ace ack aco act aea aeb aec aee aek aeo aet aka akb akc ake akk ako aoa aob aoc aoe aok aoo aot at- ata atb atc ate ato att baa bab bac bae bak bao bat bba bbb bbc bbe bbk bbo bbt bca bcb bcc bce bck bco bct be- bea beb bec bee bek beo bet bka bkb bkc bke bkk bko bkt boa bob boc boe bok boo bot bta btb btc bte btk bto btt c-- caa cab cac cae cak cao cat cba cbb cbc cbe cbk cbo cbt cca ccb ccc cce cck cco cct ce- cea ceb cec cee cek ceo cet cka ckb ckc cko ckt co- coa cob coc coe cok coo cot cta ctb ctc cte ctk cto ctt eaa eab eac eae eak eao eat eba ebb ebc ebe ebk ebo ebt ec- eca ecb ecc ece eck eco ect eea eeb eec eee eek eeo eet eka ekb ekc eke eko ekt eo- eoa eob eoc eoe eok eoo eot eta etb etc ete etk eto ett k-t ka- kaa kab kac kae kak kao kat kba kbb kbc kbe kbk kbo kca kcb kcc kce kck kct ke- kea keb kec kee kek keo ket kkb kkc kke kkk kkt koa kob koc koe kok koo kot kta ktb ktc kte ktk kto ktt oaa oab oac oae oak oao oat ob- oba obb obc obe obk obo obt oc- oca ocb occ ock oco oct oea oeb oec oee oeo oet oka okb okc oke okk oko oo- ooa oob ooc ook ooo oot ot- ota otb otc ote otk oto ott taa tab tac tae tak tao tat tba tbb tbc tbe tbk tbo tbt tca tcb tcc tce tck tco tct te- tea teb tec tee tek teo tet tka tkb tkc tke tkk tko tkt to- toa tob toc toe tok too tot tta ttb ttc tte ttk tto ttt