a-a a-b a-i a-t aaa aab aae aai aak aao aas aat ab- aba abb abe abi abk abo abs abt aea aeb aee aei aek aeo aes aet ai- aia aib aie aii aik aio ais ait aka akb ake aki akk ako aks aoa aob aoe aoi aok aoo aos aot as- asa asb ase asi ask aso ass ast at- ata atb ate ati ato ats att baa bab bae bai bak bao bas bat bba bbb bbe bbi bbk bbo bbs bbt be- bea beb bee bei bek beo bes bet bi- bia bib bie bii bik bio bis bit bka bkb bke bkk bko bks bkt boa bob boe boi bok boo bos bot bsa bsb bse bsi bsk bso bss bst bta btb bte bti btk bto bts btt eaa eab eae eai eak eao eas eat eba ebb ebe ebi ebk ebo ebs ebt eea eeb eee eek eeo ees eet eia eib eie eii eik eio eis eit eka ekb eke eki eko eks ekt eo- eoa eob eoe eoi eok eoo eos eot es- esa esb ese esi esk eso ess est eta etb ete eti etk eto ets ett ia- iaa iab iae iai iao ias iat iba ibb ibe ibi ibk ibo ibs ibt ie- iea iee iei iek ies iet iia iib iie iii iio iis iit ika ikb ike iki ikk iko iks ikt io- ioa iob ioe ioi ioo ios iot is- isa isb ise isi isk iso iss ist ita itb ite iti itk ito its itt k-t ka- kaa kab kae kai kak kao kas kat kba kbb kbe kbi kbk kbo kbs ke- kea keb kee kei kek keo kes ket kia kib kie kii kik kio kis kit kkb kke kki kkk kks kkt koa kob koe koi kok koo kos kot ksa ksb kse ksi ksk kso kss kst kta ktb kte ktk kto kts ktt o-i oaa oab oae oai oak oao oas oat ob- oba obb obe obi obk obo obs obt oea oeb oee oei oeo oes oet oia oib oie oii oik oio ois oit oka okb oke oki okk oko oks oo- ooa oob ooi ook ooo oos oot os- osa osb ose osi osk oso oss ost ot- ota otb ote oti otk oto ots ott saa sab sae sai sak sao sas sat sba sbb sbe sbi sbk sbo sbs sbt se- sea seb see sei sek seo ses set sia sib sie sii sik sio sis sit sk- ska skb ske ski skk sko sks skt soa sob soe soi sok soo sos sot ss- ssa ssb sse ssi ssk sso sss sst sta stb ste sti stk sto sts stt taa tab tae tai tak tao tas tat tba tbb tbe tbi tbk tbo tbs tbt te- tea teb tee tei tek teo tes tet tia tib tie tii tik tio tis tit tka tkb tke tkk tko tks tkt to- toa tob toe toi tok too tos tot tsa tsb tse tsi tsk tso tss tst tta ttb tte tti ttk tto tts ttt