-er eee eem eep eer ees eet em- eme emm emp emr ems emt ep- epe epm epp epr eps ept ere erm erp err ers ert es- ese esm esp esr ess est ete etm etp etr ets ett m-r mee mem mep mer mes met mme mmm mmp mmr mms mmt mpe mpm mpp mpr mps mpt mre mrm mrp mrr mrs mrt mse msm msp msr mss mst mte mtm mtp mtr mts mtt p-p pee pem pep per pes pet pme pmm pmp pmr pms pmt ppe ppm ppp ppr pps ppt pre prm prp prr prs prt ps- pse psm psp psr pss pst pt- pte ptm ptp ptr pts ptt re- ree rem rep rer res ret rme rmm rmp rmr rms rmt rpe rpm rpp rpr rps rpt rrm rrp rrr rrs rrt rse rsm rsp rsr rss rst rte rtm rtp rtr rts rtt se- see sem sep ser ses set sme smm smp smr sms smt spe spm spp spr sps spt sr- sre srm srp srr srs srt ss- sse ssm ssp ssr sss sst ste stm stp str sts stt te- tee tem tep ter tes tet tme tmm tmp tmr tms tmt tpe tpm tpp tpr tps tpt tre trm trp trr trs trt tse tsm tsp tsr tss tst tte ttm ttp ttr tts ttt