-er ddd dde ddi ddp ddr ddt ddx de- ded dee dei dep der det dex di- did die dii dip dir dit dix dpd dpe dpi dpp dpr dpt drd dre dri drp drr drt drx dtd dte dti dtp dtr dtt dtx dxd dxi dxp dxr dxt dxx ed- edd ede edi edp edr edt edx eed eee eep eer eet eex eid eie eii eip eir eit eix ep- epd epe epi epp epr ept epx erd ere eri erp err ert etd ete eti etp etr ett etx ex- exd exe exi exp exr ext exx i-d idd ide idi idp idr idt idx ie- ied iee iei iep ier iet iex iid iie iii iip iir iit iix ipd ipe ipi ipp ipr ipt ipx ir- ird ire iri irp irr irt irx itd ite iti itp itt itx ixe ixi p-p pdd pde pdi pdp pdr pdt pdx ped pee pei pep per pet pex pid pie pii pip pir pit pix ppd ppe ppi ppp ppr ppt ppx prd pre pri prp prr prt prx pt- ptd pte pti ptp ptr ptt ptx pxe pxr pxt rdd rde rdi rdp rdr rdt rdx re- red ree rei rep rer ret rex rid rie rii rip rir rit rix rpd rpe rpi rpp rpr rpt rpx rrd rri rrp rrr rrt rtd rte rti rtp rtr rtt rtx rxp rxr t-x tdd tde tdi tdp tdr tdt tdx te- ted tee tei tep ter tet tex tid tie tii tip tir tit tix tpd tpe tpi tpp tpr tpt tpx trd tre tri trp trr trt trx ttd tte tti ttp ttr ttt ttx txe txi txt xde xdi xdr xdt xed xee xep xer xet xex xie xii xit xix xpd xpe xpp xpt xrd xrt xrx xti xtp xtr xtx xxi xxp xxx