-er a-a a-b a-t aaa aab aad aae aan aao aar aat ab- aba abb abd abe abn abo abr abt ad- ada adb add ade adn ado adr adt aea aeb aed aee aen aeo aer aet an- ana anb and ane ann ano anr ant aoa aob aod aoe aon aoo aor aot ar- ara arb ard are arn aro arr art at- ata atb atd ate atn ato atr att baa bab bad bae ban bao bar bat bba bbb bbd bbe bbn bbo bbr bbt bda bdb bdd bde bdo bdr bdt be- bea beb bed bee ben beo ber bet bna bnb bnd bne bnn bno bnr bnt boa bob bod boe bon boo bor bot bra brb brd bre brn bro brr brt bta btb btd bte btn bto btr btt daa dab dad dae dan dao dar dat dba dbb dbd dbe dbn dbo dbr dbt dda ddb ddd dde ddn ddo ddr ddt de- dea deb ded dee den deo der det dna dnb dnd dne dnn dno dnr dnt doa dob dod doe don doo dor dot dra drb drd dre drn dro drr drt dta dtb dtd dte dtn dto dtr dtt eaa eab ead eae ean eao ear eat eba ebb ebd ebe ebn ebo ebr ebt ed- eda edb edd ede edn edo edr edt eea eeb eed eee een eeo eer eet en- ena enb end ene enn eno enr ent eo- eoa eob eod eoe eon eoo eor eot era erb erd ere ern ero err ert eta etb etd ete etn eto etr ett naa nab nad nae nan nao nar nat nba nbb nbd nbe nbn nbo nbr nbt nda ndb ndd nde ndn ndo ndr ndt ne- nea neb ned nee nen neo ner net nna nnb nne nnn nno nnt no- noa nob nod noe non noo nor not nra nrb nrd nre nrn nro nrr nrt nta ntb ntd nte ntn nto ntr ntt oaa oab oad oae oan oao oar oat ob- oba obb obd obe obn obo obr obt oda odb odd ode odn odo odr odt oea oeb oed oee oen oeo oer oet on- ona onb ond one onn ono onr ont oo- ooa oob ood oon ooo oor oot or- ora orb ord ore orn oro orr ort ot- ota otb otd ote otn oto otr ott ra- raa rab rad rae ran rao rar rat rba rbb rbd rbe rbn rbo rbr rbt rda rdb rdd rde rdn rdo rdr rdt re- rea reb red ree ren reo rer ret rna rnb rnd rnn rno rnr rnt roa rob rod roe ron roo ror rot rra rrb rrd rrn rrr rrt rta rtb rtd rte rtn rto rtr rtt taa tab tad tae tan tao tar tat tba tbb tbd tbe tbn tbo tbr tbt tda tdb tdd tde tdn tdo tdr tdt te- tea teb ted tee ten teo ter tet tna tnb tnd tne tnn tno tnr tnt to- toa tob tod toe ton too tor tot tra trb trd tre trn tro trr trt tta ttb ttd tte ttn tto ttr ttt