a-a a-b a-t aaa aab aae aak aan aao aas aat ab- aba abb abe abk abn abo abs abt aea aeb aee aek aen aeo aes aet aka akb ake akk akn ako aks an- ana anb ane ank ann ano ans ant aoa aob aoe aok aon aoo aos aot as- asa asb ase ask asn aso ass ast at- ata atb ate atn ato ats att baa bab bae bak ban bao bas bat bba bbb bbe bbk bbn bbo bbs bbt be- bea beb bee bek ben beo bes bet bka bkb bke bkk bkn bko bks bkt bna bnb bne bnk bnn bno bns bnt boa bob boe bok bon boo bos bot bsa bsb bse bsk bsn bso bss bst bta btb bte btk btn bto bts btt eaa eab eae eak ean eao eas eat eba ebb ebe ebk ebn ebo ebs ebt eea eeb eee eek een eeo ees eet eka ekb eke eko eks ekt en- ena enb ene enk enn eno ens ent eo- eoa eob eoe eok eon eoo eos eot es- esa esb ese esk esn eso ess est eta etb ete etk etn eto ets ett k-t ka- kaa kab kae kak kan kao kas kat kba kbb kbe kbk kbn kbo kbs ke- kea keb kee kek ken keo kes ket kkb kke kkk kkn kks kkt kn- kna kne knk knn kno knt koa kob koe kok kon koo kos kot ksa ksb kse ksk ksn kso kss kst kta ktb kte ktk ktn kto kts ktt naa nab nae nak nan nao nas nat nba nbb nbe nbk nbn nbo nbs nbt ne- nea neb nee nek nen neo nes net nka nke nkk nkn nko nks nkt nna nnb nne nnk nnn nno nns nnt no- noa nob noe nok non noo nos not nsa nsb nse nsk nsn nso nss nst nta ntb nte ntk ntn nto nts ntt oaa oab oae oak oan oao oas oat ob- oba obb obe obk obn obo obs obt oea oeb oee oen oeo oes oet oka okb oke okk oko oks on- ona onb one onk onn ono ons ont oo- ooa oob ook oon ooo oos oot os- osa osb ose osk osn oso oss ost ot- ota otb ote otk otn oto ots ott saa sab sae sak san sao sas sat sba sbb sbe sbk sbn sbo sbs sbt se- sea seb see sek sen seo ses set sk- ska skb ske skk sko sks skt sna snb sne snk snn sno sns snt soa sob soe sok son soo sos sot ss- ssa ssb sse ssk ssn sso sss sst sta stb ste stk stn sto sts stt taa tab tae tak tan tao tas tat tba tbb tbe tbk tbn tbo tbs tbt te- tea teb tee tek ten teo tes tet tka tkb tke tkk tko tks tkt tna tnb tne tnk tnn tno tns tnt to- toa tob toe tok ton too tos tot tsa tsb tse tsk tsn tso tss tst tta ttb tte ttk ttn tto tts ttt