-er ddd dde ddi ddk ddo ddp ddr dds ddt de- ded dee dei dek deo dep der des det di- did die dii dik dio dip dir dis dit dke dki dkk dko dkp dkr dks dkt dod doe doi dok doo dop dor dos dot dpd dpe dpi dpk dpo dpp dpr dps dpt drd dre dri drk dro drp drr drs drt dsd dse dsi dsk dso dsp dsr dss dst dtd dte dti dtk dto dtp dtr dts dtt ed- edd ede edi edk edo edp edr eds edt eed eee eek eeo eep eer ees eet eid eie eii eik eio eip eir eis eit ekd eke eki eko ekp ekr eks ekt eo- eod eoe eoi eok eoo eop eor eos eot ep- epd epe epi epo epp epr eps ept erd ere eri erk ero erp err ers ert es- esd ese esi esk eso esp esr ess est etd ete eti etk eto etp etr ets ett i-d idd ide idi idk ido idp idr ids idt ie- ied iee iei iek iep ier ies iet iid iie iii iio iip iir iis iit ike iki ikk iko ikr iks ikt io- iod ioe ioi ioo iop ior ios iot ipd ipe ipi ipo ipp ipr ips ipt ir- ird ire iri irk iro irp irr irs irt is- isd ise isi isk iso isp isr iss ist itd ite iti itk ito itp its itt k-t kde kdk kdo kdp kdr kds kdt ke- ked kee kei kek keo kep ker kes ket kid kie kii kik kio kip kir kis kit kke kki kkk kkp kkr kks kkt kod koe koi kok koo kop kor kos kot kpd kpe kpi kpk kpo kpp kpr kps kpt krd kri krk kro krp krr krs krt ksd kse ksi ksk kso ksp ksr kss kst kte ktk kto ktp ktr kts ktt o-i odd ode odi odo odp odr ods odt oed oee oei oeo oep oer oes oet oid oie oii oik oio oip oir ois oit okd oke oki okk oko okp okr oks oo- ood ooi ook ooo oop oor oos oot op- opd ope opi opk opo opp opr ops opt or- ord ore ori ork oro orp orr ors ort os- osd ose osi osk oso osp osr oss ost ot- otd ote oti otk oto otp otr ots ott p-p pdd pde pdi pdk pdo pdp pdr pds pdt ped pee pei pek peo pep per pes pet pid pie pii pik pio pip pir pis pit pkd pke pki pko pkp pkr pks pkt pod poe poi pok poo pop por pos pot ppd ppe ppi ppk ppo ppp ppr pps ppt prd pre pri prk pro prp prr prs prt ps- psd pse psi psk pso psp psr pss pst pt- ptd pte pti ptk pto ptp ptr pts ptt rdd rde rdi rdo rdp rdr rds rdt re- red ree rei rek reo rep rer res ret rid rie rii rik rio rip rir ris rit rke rkk rko rkp rks rkt rod roe roi rok roo rop ror ros rot rpd rpe rpi rpk rpo rpp rpr rps rpt rrd rri rrk rrp rrr rrs rrt rsd rse rsi rsk rso rsp rsr rss rst rtd rte rti rtk rto rtp rtr rts rtt sdd sde sdi sdk sdo sdp sdr sds sdt se- sed see sei sek seo sep ser ses set sid sie sii sik sio sip sir sis sit sk- skd ske ski skk sko skp skr sks skt sod soe soi sok soo sop sor sos sot spd spe spi spk spo spp spr sps spt sr- srd sre sri srk sro srp srr srs srt ss- ssd sse ssi ssk sso ssp ssr sss sst std ste sti stk sto stp str sts stt tdd tde tdi tdk tdo tdp tdr tds tdt te- ted tee tei tek teo tep ter tes tet tid tie tii tik tio tip tir tis tit tke tkk tko tkp tkr tks tkt to- tod toe toi tok too top tor tos tot tpd tpe tpi tpk tpo tpp tpr tps tpt trd tre tri trk tro trp trr trs trt tsd tse tsi tsk tso tsp tsr tss tst ttd tte tti ttk tto ttp ttr tts ttt