-er eee eef eeo eep eer ees eet ef- efe eff efo efp efr efs eft eo- eoe eof eoo eop eor eos eot ep- epe epf epo epp epr eps ept ere erf ero erp err ers ert es- ese esf eso esp esr ess est ete etf eto etp etr ets ett fee fef feo fep fer fes fet ffe fff ffo ffp ffr ffs fft foe fof foo fop for fos fot fpe fpo fpp fpr fps fpt fre frf fro frp frr frs frt fse fsf fso fsp fsr fss fst fte ftf fto ftp ftr fts ftt oee oef oeo oep oer oes oet of- ofe off ofo ofp ofr ofs oft oo- oof ooo oop oor oos oot op- ope opf opo opp opr ops opt or- ore orf oro orp orr ors ort os- ose osf oso osp osr oss ost ot- ote otf oto otp otr ots ott p-p pee pef peo pep per pes pet pfe pff pfo pfp pfr pfs pft poe pof poo pop por pos pot ppe ppf ppo ppp ppr pps ppt pre prf pro prp prr prs prt ps- pse psf pso psp psr pss pst pt- pte ptf pto ptp ptr pts ptt re- ree ref reo rep rer res ret rfe rff rfo rfp rfr rfs rft roe rof roo rop ror ros rot rpe rpf rpo rpp rpr rps rpt rrf rrp rrr rrs rrt rse rsf rso rsp rsr rss rst rte rtf rto rtp rtr rts rtt se- see sef seo sep ser ses set sfe sff sfo sfp sfr sfs sft soe sof soo sop sor sos sot spe spf spo spp spr sps spt sr- sre srf sro srp srr srs srt ss- sse ssf sso ssp ssr sss sst ste stf sto stp str sts stt te- tee tef teo tep ter tes tet tfe tff tfo tfp tfr tfs tft to- toe tof too top tor tos tot tpe tpf tpo tpp tpr tps tpt tre trf tro trp trr trs trt tse tsf tso tsp tsr tss tst tte ttf tto ttp ttr tts ttt