-er a-a a-b aaa aab aad aae aam aao aar aax ab- aba abb abd abe abm abo abr abx ad- ada adb add ade adm ado adr adx aea aeb aed aee aem aeo aer aex ama amb amd ame amm amo amr amx aoa aob aod aoe aom aoo aor aox ar- ara arb ard are arm aro arr arx ax- axa axe axm axo axr axx baa bab bad bae bam bao bar bax bba bbb bbd bbe bbm bbo bbr bbx bda bdb bdd bde bdm bdo bdr bdx be- bea beb bed bee bem beo ber bex bma bmb bmd bme bmm bmo bmr bmx boa bob bod boe bom boo bor box bra brb brd bre brm bro brr brx bxb bxd bxm bxo bxx daa dab dad dae dam dao dar dax dba dbb dbd dbe dbm dbo dbr dbx dda ddb ddd dde ddm ddo ddr ddx de- dea deb ded dee dem deo der dex dma dmb dmd dme dmm dmo dmr dmx doa dob dod doe dom doo dor dox dra drb drd dre drm dro drr drx dxd dxo dxr dxx eaa eab ead eae eam eao ear eax eba ebb ebd ebe ebm ebo ebr ebx ed- eda edb edd ede edm edo edr edx eea eeb eed eee eem eeo eer eex em- ema emb emd eme emm emo emr emx eo- eoa eob eod eoe eom eoo eor era erb erd ere erm ero err ex- exa exd exe exo exr exx m-o m-r maa mab mad mae mam mao mar max mba mbb mbd mbe mbm mbo mbr mbx mda mdb mdd mde mdm mdo mdr mdx mea meb med mee mem meo mer mex mma mmb mmd mme mmm mmo mmr mmx moa mob mod moe mom moo mor mox mra mrb mrd mre mrm mro mrr mrx mxa mxd mxr oaa oab oad oae oam oao oar oax ob- oba obb obd obe obm obo obr obx oda odb odd ode odm odo odr oea oeb oed oee oem oeo oer oex om- oma omb omd ome omm omo omr omx oo- ooa oob ood oom ooo oor oox or- ora orb ord ore orm oro orr orx ox- oxa oxb oxo oxx ra- raa rab rad rae ram rao rar rax rba rbb rbd rbe rbm rbo rbr rbx rda rdb rdd rde rdm rdo rdr rdx re- rea reb red ree rem reo rer rex rma rmb rmd rme rmm rmo rmr rmx roa rob rod roe rom roo ror rox rra rrb rrd rrm rrr rxr xaa xad xam xar xbe xbr xbx xda xdb xde xdm xdr xed xee xem xer xex xma xmd xmm xmo xmr xmx xoa xod xom xoo xor xox xrd xrx xxo xxx