-er a-a a-b a-i a-t aaa aab aae aai aan aao aar aat ab- aba abb abe abi abn abo abr abt aea aeb aee aei aen aeo aer aet ai- aia aib aie aii ain aio air ait an- ana anb ane ani ann ano anr ant aoa aob aoe aoi aon aoo aor aot ar- ara arb are ari arn aro arr art at- ata atb ate ati atn ato atr att baa bab bae bai ban bao bar bat bba bbb bbe bbi bbn bbo bbr bbt be- bea beb bee bei ben beo ber bet bi- bia bib bie bii bin bio bir bit bna bnb bne bni bnn bno bnr bnt boa bob boe boi bon boo bor bot bra brb bre bri brn bro brr brt bta btb bte bti btn bto btr btt eaa eab eae eai ean eao ear eat eba ebb ebe ebi ebn ebo ebr ebt eea eeb eee een eeo eer eet eia eib eie eii ein eio eir eit en- ena enb ene eni enn eno enr ent eo- eoa eob eoe eoi eon eoo eor eot era erb ere eri ern ero err ert eta etb ete eti etn eto etr ett ia- iaa iab iae iai ian iao iar iat iba ibb ibe ibi ibn ibo ibr ibt ie- iea iee iei ien ier iet iia iib iie iii iin iio iir iit in- ina inb ine ini inn ino inr int io- ioa iob ioe ioi ion ioo ior iot ir- ira irb ire iri irn iro irr irt ita itb ite iti itn ito itt n-i naa nab nae nai nan nao nar nat nba nbb nbe nbi nbn nbo nbr nbt ne- nea neb nee nei nen neo ner net nia nib nie nii nin nio nir nit nna nnb nne nni nnn nno nnt no- noa nob noe noi non noo nor not nra nrb nre nri nrn nro nrr nrt nta ntb nte nti ntn nto ntr ntt o-i oaa oab oae oai oan oao oar oat ob- oba obb obe obi obn obo obr obt oea oeb oee oei oen oeo oer oet oia oib oie oii oin oio oir oit on- ona onb one oni onn ono onr ont oo- ooa oob ooi oon ooo oor oot or- ora orb ore ori orn oro orr ort ot- ota otb ote oti otn oto otr ott ra- raa rab rae rai ran rao rar rat rba rbb rbe rbi rbn rbo rbr rbt re- rea reb ree rei ren reo rer ret ria rib rie rii rin rio rir rit rna rnb rni rnn rno rnr rnt roa rob roe roi ron roo ror rot rra rrb rri rrn rrr rrt rta rtb rte rti rtn rto rtr rtt taa tab tae tai tan tao tar tat tba tbb tbe tbi tbn tbo tbr tbt te- tea teb tee tei ten teo ter tet tia tib tie tii tin tio tir tit tna tnb tne tni tnn tno tnr tnt to- toa tob toe toi ton too tor tot tra trb tre tri trn tro trr trt tta ttb tte tti ttn tto ttr ttt