eee eef eel eem ees eet ef- efe eff efl efm efs eft ele elf ell elm els elt em- eme emf eml emm ems emt es- ese esf esl esm ess est ete etf etl etm ets ett fee fef fel fem fes fet ffe fff ffl ffm ffs fft fle flf fll flm fls flt fme fmf fml fmm fms fmt fse fsf fsl fsm fss fst fte ftf ftl ftm fts ftt lee lef lel lem les let lfe lff lfl lfm lfs lft lle llf lll llm lls llt lme lmf lml lmm lms lmt lse lsf lsl lsm lss lst lte ltf ltl ltm lts ltt m-f mee mef mel mem mes met mfe mff mfl mfm mfs mft mle mlf mll mlm mls mlt mme mmf mml mmm mms mmt mse msf msl msm mss mst mte mtf mtl mtm mts mtt se- see sef sel sem ses set sfe sff sfl sfm sfs sft sle slf sll slm sls slt sme smf sml smm sms smt ss- sse ssf ssl ssm sss sst ste stf stl stm sts stt te- tee tef tel tem tes tet tfe tff tfl tfm tfs tft tle tlf tll tlm tls tlt tme tmf tml tmm tms tmt tse tsf tsl tsm tss tst tte ttf ttl ttm tts ttt