a-a a-b a-c a-t aaa aab aac aae aak aao aap aat ab- aba abb abc abe abk abo abp abt ac- aca acb acc ace ack aco acp act aea aeb aec aee aek aeo aep aet aka akb akc ake akk ako akp aoa aob aoc aoe aok aoo aop aot ap- apa apb apc ape apk apo app apt at- ata atb atc ate ato atp att b-p baa bab bac bae bak bao bap bat bba bbb bbc bbe bbk bbo bbp bbt bca bcb bcc bce bck bco bcp bct be- bea beb bec bee bek beo bep bet bka bkb bkc bke bkk bko bkp bkt boa bob boc boe bok boo bop bot bpa bpb bpc bpe bpo bpp bpt bta btb btc bte btk bto btp btt c-- caa cab cac cae cak cao cap cat cba cbb cbc cbe cbk cbo cbp cbt cca ccb ccc cce cck cco ccp cct ce- cea ceb cec cee cek ceo cep cet cka ckb ckc cko ckt co- coa cob coc coe cok coo cop cot cpa cpb cpc cpe cpk cpo cpp cpt cta ctb ctc cte ctk cto ctp ctt eaa eab eac eae eak eao eap eat eba ebb ebc ebe ebk ebo ebp ebt ec- eca ecb ecc ece eck eco ect eea eeb eec eee eek eeo eep eet eka ekb ekc eke eko ekp ekt eo- eoa eob eoc eoe eok eoo eop eot ep- epa epb epc epe epo epp ept eta etb etc ete etk eto etp ett k-t ka- kaa kab kac kae kak kao kap kat kba kbb kbc kbe kbk kbo kbp kca kcb kcc kce kck kcp kct ke- kea keb kec kee kek keo kep ket kkb kkc kke kkk kkp kkt koa kob koc koe kok koo kop kot kpa kpc kpe kpk kpo kpp kpt kta ktb ktc kte ktk kto ktp ktt oaa oab oac oae oak oao oap oat ob- oba obb obc obe obk obo obp obt oc- oca ocb occ ock oco ocp oct oea oeb oec oee oeo oep oet oka okb okc oke okk oko okp oo- ooa oob ooc ook ooo oop oot op- opa opb opc ope opk opo opp opt ot- ota otb otc ote otk oto otp ott p-p paa pab pac pae pak pao pap pat pba pbb pbc pbe pbk pbo pbp pbt pca pcb pcc pce pck pco pcp pct pea peb pec pee pek peo pep pet pka pkb pkc pke pko pkp pkt poa pob poc poe pok poo pop pot ppa ppb ppc ppe ppk ppo ppp ppt pt- pta ptb ptc pte ptk pto ptp ptt taa tab tac tae tak tao tap tat tba tbb tbc tbe tbk tbo tbp tbt tca tcb tcc tce tck tco tcp tct te- tea teb tec tee tek teo tep tet tka tkb tkc tke tkk tko tkp tkt to- toa tob toc toe tok too top tot tpa tpb tpc tpe tpk tpo tpp tpt tta ttb ttc tte ttk tto ttp ttt