a-a a-b a-i aaa aab aae aaf aai aak aan aao aas ab- aba abb abe abf abi abk abn abo abs aea aeb aee aef aei aek aen aeo aes af- afa afb afe aff afi afk afn afo afs ai- aia aib aie aif aii aik ain aio ais aka akb ake aki akk akn ako aks an- ana anb ane anf ani ank ann ano ans aoa aob aoe aof aoi aok aon aoo aos as- asa asb ase asf asi ask asn aso ass baa bab bae baf bai bak ban bao bas bba bbb bbe bbf bbi bbk bbn bbo bbs be- bea beb bee bef bei bek ben beo bes bfa bfb bfe bff bfi bfn bfo bfs bi- bia bib bie bif bii bik bin bio bis bka bkb bke bkf bkk bkn bko bks bna bnb bne bnf bni bnk bnn bno bns boa bob boe bof boi bok bon boo bos bsa bsb bse bsf bsi bsk bsn bso bss eaa eab eae eaf eai eak ean eao eas eba ebb ebe ebf ebi ebk ebn ebo ebs eea eeb eee eef eek een eeo ees ef- efa efb efe eff efi efo efs eia eib eie eif eii eik ein eio eis eka ekb eke ekf eki eko eks en- ena enb ene enf eni enk enn eno ens eo- eoa eob eoe eof eoi eok eon eoo eos es- esa esb ese esf esi esk esn eso ess faa fab fae faf fai fak fan fao fas fba fbb fbe fbf fbi fbk fbn fbo fbs fea feb fee fef fei fek fen feo fes ffa ffe fff ffi ffk ffn ffo ffs fia fib fie fif fii fik fin fis fka fkb fkf fki fkk fna fnb fne fnf fni fnk fnn fns foa fob foe fof foi fok fon foo fos fsa fsb fse fsf fsi fsk fsn fso fss i-f ia- iaa iab iae iaf iai ian iao ias iba ibb ibe ibf ibi ibk ibn ibo ibs ie- iea iee ief iei iek ien ies ifa ifb ife iff ifi ifn ifo ifs iia iib iie iif iii iin iio iis ika ikb ike ikf iki ikk iko iks in- ina inb ine inf ini ink inn ino ins io- ioa iob ioe iof ioi ion ioo ios is- isa isb ise isf isi isk isn iso iss ka- kaa kab kae kaf kai kak kan kao kas kba kbb kbe kbf kbi kbk kbn kbo kbs ke- kea keb kee kef kei kek ken keo kes kfa kff kfi kfo kfs kia kib kie kif kii kik kin kio kis kkb kke kki kkk kkn kks kn- kna kne knf kni knk knn kno koa kob koe kof koi kok kon koo kos ksa ksb kse ksf ksi ksk ksn kso kss n-i naa nab nae naf nai nak nan nao nas nba nbb nbe nbf nbi nbk nbn nbo nbs ne- nea neb nee nef nei nek nen neo nes nfa nfb nfe nff nfi nfk nfn nfo nfs nia nib nie nif nii nik nin nio nis nka nke nkf nki nkk nkn nko nks nna nnb nne nnf nni nnk nnn nno nns no- noa nob noe nof noi nok non noo nos nsa nsb nse nsf nsi nsk nsn nso nss o-i oaa oab oae oaf oai oak oan oao oas ob- oba obb obe obf obi obk obn obo obs oea oeb oee oef oei oen oeo oes of- ofa ofb ofe off ofi ofn ofo ofs oia oib oie oif oii oik oin oio ois oka okb oke oki okk oko oks on- ona onb one onf oni onk onn ono ons oo- ooa oob oof ooi ook oon ooo oos os- osa osb ose osf osi osk osn oso oss saa sab sae saf sai sak san sao sas sba sbb sbe sbf sbi sbk sbn sbo sbs se- sea seb see sef sei sek sen seo ses sfa sfb sfe sff sfi sfk sfn sfo sfs sia sib sie sif sii sik sin sio sis sk- ska skb ske skf ski skk sko sks sna snb sne snf sni snk snn sno sns soa sob soe sof soi sok son soo sos ss- ssa ssb sse ssf ssi ssk ssn sso sss