-er a-a a-b a-i aaa aab aae aag aai aan aao aar aas ab- aba abb abe abg abi abn abo abr abs aea aeb aee aeg aei aen aeo aer aes ag- aga agb age agg agi agn ago agr ags ai- aia aib aie aig aii ain aio air ais an- ana anb ane ang ani ann ano anr ans aoa aob aoe aog aoi aon aoo aor aos ar- ara arb are arg ari arn aro arr ars as- asa asb ase asg asi asn aso asr ass baa bab bae bag bai ban bao bar bas bba bbb bbe bbg bbi bbn bbo bbr bbs be- bea beb bee beg bei ben beo ber bes bga bgb bge bgg bgi bgn bgo bgr bgs bi- bia bib bie big bii bin bio bir bis bna bnb bne bng bni bnn bno bnr bns boa bob boe bog boi bon boo bor bos bra brb bre brg bri brn bro brr brs bsa bsb bse bsg bsi bsn bso bsr bss eaa eab eae eag eai ean eao ear eas eba ebb ebe ebg ebi ebn ebo ebr ebs eea eeb eee eeg een eeo eer ees ega egb ege egg egi egn ego egr egs eia eib eie eig eii ein eio eir eis en- ena enb ene eng eni enn eno enr ens eo- eoa eob eoe eog eoi eon eoo eor eos era erb ere erg eri ern ero err ers es- esa esb ese esg esi esn eso esr ess gaa gab gae gag gai gan gao gar gas gba gbe gbg gbi gbn gbo gbr gbs ge- gea geb gee geg gei gen geo ger ges gga ggb ggg ggi ggn ggo ggr ggs gia gib gie gig gii gin gio gir gis gna gnb gne gni gnn gno gnr gns goa gob goe gog goi gon goo gor gos gra grb gre grg gri grn gro grr grs gsa gsb gse gsg gsi gsn gso gsr gss ia- iaa iab iae iag iai ian iao iar ias iba ibb ibe ibg ibi ibn ibo ibr ibs ie- iea iee ieg iei ien ier ies iga igb ige igg igi ign igo igr igs iia iib iie iii iin iio iir iis in- ina inb ine ing ini inn ino inr ins io- ioa iob ioe iog ioi ion ioo ior ios ir- ira irb ire irg iri irn iro irr irs is- isa isb ise isg isi isn iso isr iss n-i naa nab nae nag nai nan nao nar nas nba nbb nbe nbg nbi nbn nbo nbr nbs ne- nea neb nee neg nei nen neo ner nes nga ngb nge ngg ngi ngn ngo ngs nia nib nie nig nii nin nio nir nis nna nnb nne nng nni nnn nno nns no- noa nob noe nog noi non noo nor nos nra nrb nre nrg nri nrn nro nrr nrs nsa nsb nse nsg nsi nsn nso nsr nss o-i oaa oab oae oag oai oan oao oar oas ob- oba obb obe obg obi obn obo obr obs oea oeb oee oeg oei oen oeo oer oes oga oge ogg ogi ogn ogo ogs oia oib oie oii oin oio oir ois on- ona onb one ong oni onn ono onr ons oo- ooa oob oog ooi oon ooo oor oos or- ora orb ore org ori orn oro orr ors os- osa osb ose osg osi osn oso osr oss ra- raa rab rae rag rai ran rao rar ras rba rbb rbe rbg rbi rbn rbo rbr rbs re- rea reb ree reg rei ren reo rer res rga rgb rge rgg rgi rgn rgo rgr rgs ria rib rie rig rii rin rio rir ris rna rnb rng rni rnn rno rnr rns roa rob roe rog roi ron roo ror ros rra rrb rrg rri rrn rrr rrs rsa rsb rse rsg rsi rsn rso rsr rss saa sab sae sag sai san sao sar sas sba sbb sbe sbg sbi sbn sbo sbr sbs se- sea seb see seg sei sen seo ser ses sga sgb sge sgg sgi sgn sgo sgr sgs sia sib sie sig sii sin sio sir sis sna snb sne sng sni snn sno snr sns soa sob soe sog soi son soo sor sos sr- sra srb sre srg sri srn sro srr srs ss- ssa ssb sse ssg ssi ssn sso ssr sss