-er ddd dde ddi ddk ddp ddr dds de- ded dee dei dek dep der des di- did die dii dik dip dir dis dke dki dkk dkp dkr dks dpd dpe dpi dpk dpp dpr dps drd dre dri drk drp drr drs dsd dse dsi dsk dsp dsr dss ed- edd ede edi edk edp edr eds eed eee eek eep eer ees eid eie eii eik eip eir eis ekd eke eki ekp ekr eks ep- epd epe epi epp epr eps erd ere eri erk erp err ers es- esd ese esi esk esp esr ess i-d idd ide idi idk idp idr ids ie- ied iee iei iek iep ier ies iid iie iii iip iir iis ike iki ikk ikr iks ipd ipe ipi ipp ipr ips ir- ird ire iri irk irp irr irs is- isd ise isi isk isp isr iss kde kdk kdp kdr kds ke- ked kee kei kek kep ker kes kid kie kii kik kip kir kis kke kki kkk kkp kkr kks kpd kpe kpi kpk kpp kpr kps krd kri krk krp krr krs ksd kse ksi ksk ksp ksr kss p-p pdd pde pdi pdk pdp pdr pds ped pee pei pek pep per pes pid pie pii pik pip pir pis pkd pke pki pkp pkr pks ppd ppe ppi ppk ppp ppr pps prd pre pri prk prp prr prs ps- psd pse psi psk psp psr pss rdd rde rdi rdp rdr rds re- red ree rei rek rep rer res rid rie rii rik rip rir ris rke rkk rkp rks rpd rpe rpi rpk rpp rpr rps rrd rri rrk rrp rrr rrs rsd rse rsi rsk rsp rsr rss sdd sde sdi sdk sdp sdr sds se- sed see sei sek sep ser ses sid sie sii sik sip sir sis sk- skd ske ski skk skp skr sks spd spe spi spk spp spr sps sr- srd sre sri srk srp srr srs ss- ssd sse ssi ssk ssp ssr sss