a-a a-b a-c a-t aaa aab aac aae aak aan aas aat ab- aba abb abc abe abk abn abs abt ac- aca acb acc ace ack acn acs act aea aeb aec aee aek aen aes aet aka akb akc ake akk akn aks an- ana anb anc ane ank ann ans ant as- asa asb asc ase ask asn ass ast at- ata atb atc ate atn ats att baa bab bac bae bak ban bas bat bba bbb bbc bbe bbk bbn bbs bbt bca bcb bcc bce bck bcn bcs bct be- bea beb bec bee bek ben bes bet bka bkb bkc bke bkk bkn bks bkt bna bnb bnc bne bnk bnn bns bnt bsa bsb bsc bse bsk bsn bss bst bta btb btc bte btk btn bts btt c-- caa cab cac cae cak can cas cat cba cbb cbc cbe cbk cbn cbs cbt cca ccb ccc cce cck ccn ccs cct ce- cea ceb cec cee cek cen ces cet cka ckb ckc cks ckt cn- cna cnb cnc cne cnn cns cnt csa csb csc cse csk csn css cst cta ctb ctc cte ctk ctn cts ctt eaa eab eac eae eak ean eas eat eba ebb ebc ebe ebk ebn ebs ebt ec- eca ecb ecc ece eck ecn ecs ect eea eeb eec eee eek een ees eet eka ekb ekc eke eks ekt en- ena enb enc ene enk enn ens ent es- esa esb esc ese esk esn ess est eta etb etc ete etk etn ets ett k-t ka- kaa kab kac kae kak kan kas kat kba kbb kbc kbe kbk kbn kbs kca kcb kcc kce kck kcn kcs kct ke- kea keb kec kee kek ken kes ket kkb kkc kke kkk kkn kks kkt kn- kna knc kne knk knn knt ksa ksb ksc kse ksk ksn kss kst kta ktb ktc kte ktk ktn kts ktt naa nab nac nae nak nan nas nat nba nbb nbc nbe nbk nbn nbs nbt nca ncb ncc nce nck ncn ncs nct ne- nea neb nec nee nek nen nes net nka nkc nke nkk nkn nks nkt nna nnb nnc nne nnk nnn nns nnt nsa nsb nsc nse nsk nsn nss nst nta ntb ntc nte ntk ntn nts ntt saa sab sac sae sak san sas sat sba sbb sbc sbe sbk sbn sbs sbt sca scb scc sce sck scn scs sct se- sea seb sec see sek sen ses set sk- ska skb skc ske skk sks skt sna snb snc sne snk snn sns snt ss- ssa ssb ssc sse ssk ssn sss sst sta stb stc ste stk stn sts stt taa tab tac tae tak tan tas tat tba tbb tbc tbe tbk tbn tbs tbt tca tcb tcc tce tck tcn tcs tct te- tea teb tec tee tek ten tes tet tka tkb tkc tke tkk tks tkt tna tnb tnc tne tnk tnn tns tnt tsa tsb tsc tse tsk tsn tss tst tta ttb ttc tte ttk ttn tts ttt