eee eem eep ees eet em- eme emm emp ems emt ep- epe epm epp eps ept es- ese esm esp ess est ete etm etp ets ett mee mem mep mes met mme mmm mmp mms mmt mpe mpm mpp mps mpt mse msm msp mss mst mte mtm mtp mts mtt p-p pee pem pep pes pet pme pmm pmp pms pmt ppe ppm ppp pps ppt ps- pse psm psp pss pst pt- pte ptm ptp pts ptt se- see sem sep ses set sme smm smp sms smt spe spm spp sps spt ss- sse ssm ssp sss sst ste stm stp sts stt te- tee tem tep tes tet tme tmm tmp tms tmt tpe tpm tpp tps tpt tse tsm tsp tss tst tte ttm ttp tts ttt