-er ddd dde ddh ddo ddr ddx de- ded dee deh deo der dex dh- dhd dhe dhh dho dhr dod doe doh doo dor dox drd dre dro drr drx dxd dxo dxr dxx ed- edd ede edh edo edr edx eed eee eeo eer eex ehd ehe ehh eho ehr eo- eod eoe eoh eoo eor erd ere erh ero err ex- exd exe exh exo exr exx hdd hde hdh hdo hdr hdx he- hed hee heh heo her hex hhd hhe hhh hho hhr hod hoe hoh hoo hor hox hr- hrd hre hrh hro hrr hxd odd ode odh odo odr oed oee oeh oeo oer oex ohd ohe ohh oho ohr oo- ood ooh ooo oor oox or- ord ore orh oro orr orx ox- oxo oxx rdd rde rdh rdo rdr rdx re- red ree reh reo rer rex rh- rhd rhe rhh rho rhr rod roe roh roo ror rox rrd rrh rrr rxr xde xdh xdr xed xee xer xex xhd xod xoo xor xox xrd xrx xxo xxx