a-a a-b a-c a-t aaa aab aac aae aan aao aas aat ab- aba abb abc abe abn abo abs abt ac- aca acb acc ace acn aco acs act aea aeb aec aee aen aeo aes aet an- ana anb anc ane ann ano ans ant aoa aob aoc aoe aon aoo aos aot as- asa asb asc ase asn aso ass ast at- ata atb atc ate atn ato ats att baa bab bac bae ban bao bas bat bba bbb bbc bbe bbn bbo bbs bbt bca bcb bcc bce bcn bco bcs bct be- bea beb bec bee ben beo bes bet bna bnb bnc bne bnn bno bns bnt boa bob boc boe bon boo bos bot bsa bsb bsc bse bsn bso bss bst bta btb btc bte btn bto bts btt c-- caa cab cac cae can cao cas cat cba cbb cbc cbe cbn cbo cbs cbt cca ccb ccc cce ccn cco ccs cct ce- cea ceb cec cee cen ceo ces cet cn- cna cnb cnc cne cnn cno cns cnt co- coa cob coc coe con coo cos cot csa csb csc cse csn cso css cst cta ctb ctc cte ctn cto cts ctt eaa eab eac eae ean eao eas eat eba ebb ebc ebe ebn ebo ebs ebt ec- eca ecb ecc ece ecn eco ecs ect eea eeb eec eee een eeo ees eet en- ena enb enc ene enn eno ens ent eo- eoa eob eoc eoe eon eoo eos eot es- esa esb esc ese esn eso ess est eta etb etc ete etn eto ets ett naa nab nac nae nan nao nas nat nba nbb nbc nbe nbn nbo nbs nbt nca ncb ncc nce ncn nco ncs nct ne- nea neb nec nee nen neo nes net nna nnb nnc nne nnn nno nns nnt no- noa nob noc noe non noo nos not nsa nsb nsc nse nsn nso nss nst nta ntb ntc nte ntn nto nts ntt oaa oab oac oae oan oao oas oat ob- oba obb obc obe obn obo obs obt oc- oca ocb occ ocn oco ocs oct oea oeb oec oee oen oeo oes oet on- ona onb onc one onn ono ons ont oo- ooa oob ooc oon ooo oos oot os- osa osb osc ose osn oso oss ost ot- ota otb otc ote otn oto ots ott saa sab sac sae san sao sas sat sba sbb sbc sbe sbn sbo sbs sbt sca scb scc sce scn sco scs sct se- sea seb sec see sen seo ses set sna snb snc sne snn sno sns snt soa sob soc soe son soo sos sot ss- ssa ssb ssc sse ssn sso sss sst sta stb stc ste stn sto sts stt taa tab tac tae tan tao tas tat tba tbb tbc tbe tbn tbo tbs tbt tca tcb tcc tce tcn tco tcs tct te- tea teb tec tee ten teo tes tet tna tnb tnc tne tnn tno tns tnt to- toa tob toc toe ton too tos tot tsa tsb tsc tse tsn tso tss tst tta ttb ttc tte ttn tto tts ttt