-er a-a a-b aaa aab aad aae aag aan aao aar ab- aba abb abd abe abg abn abo abr ad- ada adb add ade adg adn ado adr aea aeb aed aee aeg aen aeo aer ag- aga agb agd age agg agn ago agr an- ana anb and ane ang ann ano anr aoa aob aod aoe aog aon aoo aor ar- ara arb ard are arg arn aro arr baa bab bad bae bag ban bao bar bba bbb bbd bbe bbg bbn bbo bbr bda bdb bdd bde bdg bdo bdr be- bea beb bed bee beg ben beo ber bga bgb bgd bge bgg bgn bgo bgr bna bnb bnd bne bng bnn bno bnr boa bob bod boe bog bon boo bor bra brb brd bre brg brn bro brr daa dab dad dae dag dan dao dar dba dbb dbd dbe dbg dbn dbo dbr dda ddb ddd dde ddg ddn ddo ddr de- dea deb ded dee deg den deo der dga dgd dge dgg dgn dgr dna dnb dnd dne dng dnn dno dnr doa dob dod doe dog don doo dor dra drb drd dre drg drn dro drr eaa eab ead eae eag ean eao ear eba ebb ebd ebe ebg ebn ebo ebr ed- eda edb edd ede edg edn edo edr eea eeb eed eee eeg een eeo eer ega egb egd ege egg egn ego egr en- ena enb end ene eng enn eno enr eo- eoa eob eod eoe eog eon eoo eor era erb erd ere erg ern ero err g-d gaa gab gad gae gag gan gao gar gba gbd gbe gbg gbn gbo gbr gda gdb gdd gde gdn gdo gdr ge- gea geb ged gee geg gen geo ger gga ggb ggd ggg ggn ggo ggr gna gnb gnd gne gnn gno gnr goa gob god goe gog gon goo gor gra grb grd gre grg grn gro grr naa nab nad nae nag nan nao nar nba nbb nbd nbe nbg nbn nbo nbr nda ndb ndd nde ndg ndn ndo ndr ne- nea neb ned nee neg nen neo ner nga ngb ngd nge ngg ngn ngo nna nnb nne nng nnn nno no- noa nob nod noe nog non noo nor nra nrb nrd nre nrg nrn nro nrr oaa oab oad oae oag oan oao oar ob- oba obb obd obe obg obn obo obr oda odb odd ode odg odn odo odr oea oeb oed oee oeg oen oeo oer oga ogd oge ogg ogn ogo on- ona onb ond one ong onn ono onr oo- ooa oob ood oog oon ooo oor or- ora orb ord ore org orn oro orr ra- raa rab rad rae rag ran rao rar rba rbb rbd rbe rbg rbn rbo rbr rda rdb rdd rde rdg rdn rdo rdr re- rea reb red ree reg ren reo rer rga rgb rgd rge rgg rgn rgo rgr rna rnb rnd rng rnn rno rnr roa rob rod roe rog ron roo ror rra rrb rrd rrg rrn rrr