-er ddd dde ddi ddp ddr dds de- ded dee dei dep der des di- did die dii dip dir dis dpd dpe dpi dpp dpr dps drd dre dri drp drr drs dsd dse dsi dsp dsr dss ed- edd ede edi edp edr eds eed eee eep eer ees eid eie eii eip eir eis ep- epd epe epi epp epr eps erd ere eri erp err ers es- esd ese esi esp esr ess i-d idd ide idi idp idr ids ie- ied iee iei iep ier ies iid iie iii iip iir iis ipd ipe ipi ipp ipr ips ir- ird ire iri irp irr irs is- isd ise isi isp isr iss p-p pdd pde pdi pdp pdr pds ped pee pei pep per pes pid pie pii pip pir pis ppd ppe ppi ppp ppr pps prd pre pri prp prr prs ps- psd pse psi psp psr pss rdd rde rdi rdp rdr rds re- red ree rei rep rer res rid rie rii rip rir ris rpd rpe rpi rpp rpr rps rrd rri rrp rrr rrs rsd rse rsi rsp rsr rss sdd sde sdi sdp sdr sds se- sed see sei sep ser ses sid sie sii sip sir sis spd spe spi spp spr sps sr- srd sre sri srp srr srs ss- ssd sse ssi ssp ssr sss