-er ddd dde ddp ddr ddt de- ded dee dep der det dpd dpe dpp dpr dpt drd dre drp drr drt dtd dte dtp dtr dtt ed- edd ede edp edr edt eed eee eep eer eet ep- epd epe epp epr ept erd ere erp err ert etd ete etp etr ett p-p pdd pde pdp pdr pdt ped pee pep per pet ppd ppe ppp ppr ppt prd pre prp prr prt pt- ptd pte ptp ptr ptt rdd rde rdp rdr rdt re- red ree rep rer ret rpd rpe rpp rpr rpt rrd rrp rrr rrt rtd rte rtp rtr rtt tdd tde tdp tdr tdt te- ted tee tep ter tet tpd tpe tpp tpr tpt trd tre trp trr trt ttd tte ttp ttr ttt