-er eee eef eel eem eer ees ef- efe eff efl efm efr efs ele elf ell elm elr els em- eme emf eml emm emr ems ere erf erl erm err ers es- ese esf esl esm esr ess fee fef fel fem fer fes ffe fff ffl ffm ffr ffs fle flf fll flm flr fls fme fmf fml fmm fmr fms fre frf frl frm frr frs fse fsf fsl fsm fsr fss lee lef lel lem ler les lfe lff lfl lfm lfr lfs lle llf lll llm llr lls lme lmf lml lmm lmr lms lrf lrm lrr lrs lse lsf lsl lsm lsr lss m-f m-r mee mef mel mem mer mes mfe mff mfl mfm mfr mfs mle mlf mll mlm mlr mls mme mmf mml mmm mmr mms mre mrf mrl mrm mrr mrs mse msf msl msm msr mss re- ree ref rel rem rer res rfe rff rfl rfm rfr rfs rle rlf rll rlm rlr rls rme rmf rml rmm rmr rms rrf rrl rrm rrr rrs rse rsf rsl rsm rsr rss se- see sef sel sem ser ses sfe sff sfl sfm sfr sfs sle slf sll slm slr sls sme smf sml smm smr sms sr- sre srf srl srm srr srs ss- sse ssf ssl ssm ssr sss