-er a-a a-b a-i a-t aaa aab aae aai aan aao aar aas aat ab- aba abb abe abi abn abo abr abs abt aea aeb aee aei aen aeo aer aes aet ai- aia aib aie aii ain aio air ais ait an- ana anb ane ani ann ano anr ans ant aoa aob aoe aoi aon aoo aor aos aot ar- ara arb are ari arn aro arr ars art as- asa asb ase asi asn aso asr ass ast at- ata atb ate ati atn ato atr ats att baa bab bae bai ban bao bar bas bat bba bbb bbe bbi bbn bbo bbr bbs bbt be- bea beb bee bei ben beo ber bes bet bi- bia bib bie bii bin bio bir bis bit bna bnb bne bni bnn bno bnr bns bnt boa bob boe boi bon boo bor bos bot bra brb bre bri brn bro brr brs brt bsa bsb bse bsi bsn bso bsr bss bst bta btb bte bti btn bto btr bts btt eaa eab eae eai ean eao ear eas eat eba ebb ebe ebi ebn ebo ebr ebs ebt eea eeb eee een eeo eer ees eet eia eib eie eii ein eio eir eis eit en- ena enb ene eni enn eno enr ens ent eo- eoa eob eoe eoi eon eoo eor eos eot era erb ere eri ern ero err ers ert es- esa esb ese esi esn eso esr ess est eta etb ete eti etn eto etr ets ett ia- iaa iab iae iai ian iao iar ias iat iba ibb ibe ibi ibn ibo ibr ibs ibt ie- iea iee iei ien ier ies iet iia iib iie iii iin iio iir iis iit in- ina inb ine ini inn ino inr ins int io- ioa iob ioe ioi ion ioo ior ios iot ir- ira irb ire iri irn iro irr irs irt is- isa isb ise isi isn iso isr iss ist ita itb ite iti itn ito its itt n-i naa nab nae nai nan nao nar nas nat nba nbb nbe nbi nbn nbo nbr nbs nbt ne- nea neb nee nei nen neo ner nes net nia nib nie nii nin nio nir nis nit nna nnb nne nni nnn nno nns nnt no- noa nob noe noi non noo nor nos not nra nrb nre nri nrn nro nrr nrs nrt nsa nsb nse nsi nsn nso nsr nss nst nta ntb nte nti ntn nto ntr nts ntt o-i oaa oab oae oai oan oao oar oas oat ob- oba obb obe obi obn obo obr obs obt oea oeb oee oei oen oeo oer oes oet oia oib oie oii oin oio oir ois oit on- ona onb one oni onn ono onr ons ont oo- ooa oob ooi oon ooo oor oos oot or- ora orb ore ori orn oro orr ors ort os- osa osb ose osi osn oso osr oss ost ot- ota otb ote oti otn oto otr ots ott ra- raa rab rae rai ran rao rar ras rat rba rbb rbe rbi rbn rbo rbr rbs rbt re- rea reb ree rei ren reo rer res ret ria rib rie rii rin rio rir ris rit rna rnb rni rnn rno rnr rns rnt roa rob roe roi ron roo ror ros rot rra rrb rri rrn rrr rrs rrt rsa rsb rse rsi rsn rso rsr rss rst rta rtb rte rti rtn rto rtr rts rtt saa sab sae sai san sao sar sas sat sba sbb sbe sbi sbn sbo sbr sbs sbt se- sea seb see sei sen seo ser ses set sia sib sie sii sin sio sir sis sit sna snb sne sni snn sno snr sns snt soa sob soe soi son soo sor sos sot sr- sra srb sre sri srn sro srr srs srt ss- ssa ssb sse ssi ssn sso ssr sss sst sta stb ste sti stn sto str sts stt taa tab tae tai tan tao tar tas tat tba tbb tbe tbi tbn tbo tbr tbs tbt te- tea teb tee tei ten teo ter tes tet tia tib tie tii tin tio tir tis tit tna tnb tne tni tnn tno tnr tns tnt to- toa tob toe toi ton too tor tos tot tra trb tre tri trn tro trr trs trt tsa tsb tse tsi tsn tso tsr tss tst tta ttb tte tti ttn tto ttr tts ttt