-er a-a a-b aaa aab aad aae aaf aam aao aar ab- aba abb abd abe abf abm abo abr ad- ada adb add ade adf adm ado adr aea aeb aed aee aef aem aeo aer af- afa afb afd afe aff afm afo afr ama amb amd ame amf amm amo amr aoa aob aod aoe aof aom aoo aor ar- ara arb ard are arf arm aro arr baa bab bad bae baf bam bao bar bba bbb bbd bbe bbf bbm bbo bbr bda bdb bdd bde bdf bdm bdo bdr be- bea beb bed bee bef bem beo ber bfa bfb bfd bfe bff bfm bfo bfr bma bmb bmd bme bmf bmm bmo bmr boa bob bod boe bof bom boo bor bra brb brd bre brf brm bro brr daa dab dad dae daf dam dao dar dba dbb dbd dbe dbf dbm dbo dbr dda ddb ddd dde ddf ddm ddo ddr de- dea deb ded dee def dem deo der dfa dfb dfd dfe dff dfm dfo dfr dma dmb dmd dme dmf dmm dmo dmr doa dob dod doe dof dom doo dor dra drb drd dre drm dro drr eaa eab ead eae eaf eam eao ear eba ebb ebd ebe ebf ebm ebo ebr ed- eda edb edd ede edf edm edo edr eea eeb eed eee eef eem eeo eer ef- efa efb efd efe eff efm efo efr em- ema emb emd eme emf emm emo emr eo- eoa eob eod eoe eof eom eoo eor era erb erd ere erf erm ero err faa fab fad fae faf fam fao far fba fbb fbd fbe fbf fbm fbo fbr fda fdb fdd fde fdf fdm fdo fdr fea feb fed fee fef fem feo fer ffa ffd ffe fff ffm ffo ffr fma fmb fmd fme fmf fmm fmo fmr foa fob foe fof fom foo for fra frb frd fre frf frm fro frr m-f m-o m-r maa mab mad mae maf mam mao mar mba mbb mbd mbe mbf mbm mbo mbr mda mdb mdd mde mdf mdm mdo mdr mea meb med mee mef mem meo mer mfa mfb mfd mfe mff mfm mfo mfr mma mmb mmd mme mmf mmm mmo mmr moa mob mod moe mof mom moo mor mra mrb mrd mre mrf mrm mro mrr oaa oab oad oae oaf oam oao oar ob- oba obb obd obe obf obm obo obr oda odb odd ode odf odm odo odr oea oeb oed oee oef oem oeo oer of- ofa ofb ofd ofe off ofm ofo ofr om- oma omb omd ome omf omm omo omr oo- ooa oob ood oof oom ooo oor or- ora orb ord ore orf orm oro orr ra- raa rab rad rae raf ram rao rar rba rbb rbd rbe rbf rbm rbo rbr rda rdb rdd rde rdf rdm rdo rdr re- rea reb red ree ref rem reo rer rfa rfb rfd rfe rff rfm rfo rfr rma rmb rmd rme rmf rmm rmo rmr roa rob rod roe rof rom roo ror rra rrb rrd rrf rrm rrr