-er ddd dde ddf ddp ddr dds de- ded dee def dep der des dfd dfe dff dfp dfr dfs dpd dpe dpf dpp dpr dps drd dre drp drr drs dsd dse dsf dsp dsr dss ed- edd ede edf edp edr eds eed eee eef eep eer ees ef- efd efe eff efp efr efs ep- epd epe epf epp epr eps erd ere erf erp err ers es- esd ese esf esp esr ess fdd fde fdf fdp fdr fds fed fee fef fep fer fes ffd ffe fff ffp ffr ffs fpd fpe fpp fpr fps frd fre frf frp frr frs fsd fse fsf fsp fsr fss p-p pdd pde pdf pdp pdr pds ped pee pef pep per pes pfd pfe pff pfp pfr pfs ppd ppe ppf ppp ppr pps prd pre prf prp prr prs ps- psd pse psf psp psr pss rdd rde rdf rdp rdr rds re- red ree ref rep rer res rfd rfe rff rfp rfr rfs rpd rpe rpf rpp rpr rps rrd rrf rrp rrr rrs rsd rse rsf rsp rsr rss sdd sde sdf sdp sdr sds se- sed see sef sep ser ses sfd sfe sff sfp sfr sfs spd spe spf spp spr sps sr- srd sre srf srp srr srs ss- ssd sse ssf ssp ssr sss