-er ddd dde ddf ddo ddr ddt de- ded dee def deo der det dfd dfe dff dfo dfr dft dod doe dof doo dor dot drd dre dro drr drt dtd dte dtf dto dtr dtt ed- edd ede edf edo edr edt eed eee eef eeo eer eet ef- efd efe eff efo efr eft eo- eod eoe eof eoo eor eot erd ere erf ero err ert etd ete etf eto etr ett fdd fde fdf fdo fdr fdt fed fee fef feo fer fet ffd ffe fff ffo ffr fft foe fof foo for fot frd fre frf fro frr frt ftd fte ftf fto ftr ftt odd ode odf odo odr odt oed oee oef oeo oer oet of- ofd ofe off ofo ofr oft oo- ood oof ooo oor oot or- ord ore orf oro orr ort ot- otd ote otf oto otr ott rdd rde rdf rdo rdr rdt re- red ree ref reo rer ret rfd rfe rff rfo rfr rft rod roe rof roo ror rot rrd rrf rrr rrt rtd rte rtf rto rtr rtt tdd tde tdf tdo tdr tdt te- ted tee tef teo ter tet tfd tfe tff tfo tfr tft to- tod toe tof too tor tot trd tre trf tro trr trt ttd tte ttf tto ttr ttt