a-a a-b a-i aaa aab aae aaf aai aan aao aas ab- aba abb abe abf abi abn abo abs aea aeb aee aef aei aen aeo aes af- afa afb afe aff afi afn afo afs ai- aia aib aie aif aii ain aio ais an- ana anb ane anf ani ann ano ans aoa aob aoe aof aoi aon aoo aos as- asa asb ase asf asi asn aso ass baa bab bae baf bai ban bao bas bba bbb bbe bbf bbi bbn bbo bbs be- bea beb bee bef bei ben beo bes bfa bfb bfe bff bfi bfn bfo bfs bi- bia bib bie bif bii bin bio bis bna bnb bne bnf bni bnn bno bns boa bob boe bof boi bon boo bos bsa bsb bse bsf bsi bsn bso bss eaa eab eae eaf eai ean eao eas eba ebb ebe ebf ebi ebn ebo ebs eea eeb eee eef een eeo ees ef- efa efb efe eff efi efo efs eia eib eie eif eii ein eio eis en- ena enb ene enf eni enn eno ens eo- eoa eob eoe eof eoi eon eoo eos es- esa esb ese esf esi esn eso ess faa fab fae faf fai fan fao fas fba fbb fbe fbf fbi fbn fbo fbs fea feb fee fef fei fen feo fes ffa ffe fff ffi ffn ffo ffs fia fib fie fif fii fin fis fna fnb fne fnf fni fnn fns foa fob foe fof foi fon foo fos fsa fsb fse fsf fsi fsn fso fss i-f ia- iaa iab iae iaf iai ian iao ias iba ibb ibe ibf ibi ibn ibo ibs ie- iea iee ief iei ien ies ifa ifb ife iff ifi ifn ifo ifs iia iib iie iif iii iin iio iis in- ina inb ine inf ini inn ino ins io- ioa iob ioe iof ioi ion ioo ios is- isa isb ise isf isi isn iso iss n-i naa nab nae naf nai nan nao nas nba nbb nbe nbf nbi nbn nbo nbs ne- nea neb nee nef nei nen neo nes nfa nfb nfe nff nfi nfn nfo nfs nia nib nie nif nii nin nio nis nna nnb nne nnf nni nnn nno nns no- noa nob noe nof noi non noo nos nsa nsb nse nsf nsi nsn nso nss o-i oaa oab oae oaf oai oan oao oas ob- oba obb obe obf obi 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 oin oio ois on- ona onb one onf oni onn ono ons oo- ooa oob oof ooi oon ooo oos os- osa osb ose osf osi osn oso oss saa sab sae saf sai san sao sas sba sbb sbe sbf sbi sbn sbo sbs se- sea seb see sef sei sen seo ses sfa sfb sfe sff sfi sfn sfo sfs sia sib sie sif sii sin sio sis sna snb sne snf sni snn sno sns soa sob soe sof soi son soo sos ss- ssa ssb sse ssf ssi ssn sso sss