a-a a-b a-c a-t aaa aab aac aae aao aap aat ab- aba abb abc abe abo abp abt ac- aca acb acc ace aco acp act aea aeb aec aee aeo aep aet aoa aob aoc aoe aoo aop aot ap- apa apb apc ape apo app apt at- ata atb atc ate ato atp att b-p baa bab bac bae bao bap bat bba bbb bbc bbe bbo bbp bbt bca bcb bcc bce bco bcp bct be- bea beb bec bee beo bep bet boa bob boc boe boo bop bot bpa bpb bpc bpe bpo bpp bpt bta btb btc bte bto btp btt c-- caa cab cac cae cao cap cat cba cbb cbc cbe cbo cbp cbt cca ccb ccc cce cco ccp cct ce- cea ceb cec cee ceo cep cet co- coa cob coc coe coo cop cot cpa cpb cpc cpe cpo cpp cpt cta ctb ctc cte cto ctp ctt eaa eab eac eae eao eap eat eba ebb ebc ebe ebo ebp ebt ec- eca ecb ecc ece eco ect eea eeb eec eee eeo eep eet eo- eoa eob eoc eoe eoo eop eot ep- epa epb epc epe epo epp ept eta etb etc ete eto etp ett oaa oab oac oae oao oap oat ob- oba obb obc obe obo obp obt oc- oca ocb occ oco ocp oct oea oeb oec oee oeo oep oet oo- ooa oob ooc ooo oop oot op- opa opb opc ope opo opp opt ot- ota otb otc ote oto otp ott p-p paa pab pac pae pao pap pat pba pbb pbc pbe pbo pbp pbt pca pcb pcc pce pco pcp pct pea peb pec pee peo pep pet poa pob poc poe poo pop pot ppa ppb ppc ppe ppo ppp ppt pt- pta ptb ptc pte pto ptp ptt taa tab tac tae tao tap tat tba tbb tbc tbe tbo tbp tbt tca tcb tcc tce tco tcp tct te- tea teb tec tee teo tep tet to- toa tob toc toe too top tot tpa tpb tpc tpe tpo tpp tpt tta ttb ttc tte tto ttp ttt