eee eem ees eet eex em- eme emm ems emt emx es- ese esm ess est esx ete etm ets ett etx ex- exe exs ext exx mee mem mes met mex mme mmm mms mmt mmx mse msm mss mst msx mte mtm mts mtt mtx mxs se- see sem ses set sex sme smm sms smt smx ss- sse ssm sss sst ssx ste stm sts stt stx sxm sxs sxt t-x te- tee tem tes tet tex tme tmm tms tmt tmx tse tsm tss tst tsx tte ttm tts ttt ttx txe txs txt xee xem xes xet xex xmm xms xmt xmx xsm xss xst xtm xts xtx xxx