-er eee eef eem eep eer ees ef- efe eff efi efm efp efr efs eie eif eii eim eip eir eis em- eme emf emi emm emp emr ems ep- epe epf epi epm epp epr eps ere erf eri erm erp err ers es- ese esf esi esm esp esr ess fee fef fei fem fep fer fes ffe fff ffi ffm ffp ffr ffs fie fif fii fim fip fir fis fme fmf fmi fmm fmp fmr fms fpe fpi fpm fpp fpr fps fre frf fri frm frp frr frs fse fsf fsi fsm fsp fsr fss i-f ie- iee ief iei iem iep ier ies ife iff ifi ifm ifp ifr ifs iie iif iii iim iip iir iis im- ime imf imi imm imp ims ipe ipf ipi ipm ipp ipr ips ir- ire irf iri irm irp irr irs is- ise isf isi ism isp isr iss m-f m-r mee mef mei mem mep mer mes mfe mff mfi mfm mfp mfr mfs mi- mie mif mii mim mip mir mis mme mmf mmi mmm mmp mmr mms mpe mpf mpi mpm mpp mpr mps mre mrf mri mrm mrp mrr mrs mse msf msi msm msp msr mss p-p pee pef pei pem pep per pes pfe pff pfi pfm pfp pfr pfs pie pif pii pim pip pir pis pme pmf pmi pmm pmp pmr pms ppe ppf ppi ppm ppp ppr pps pre prf pri prm prp prr prs ps- pse psf psi psm psp psr pss re- ree ref rei rem rep rer res rfe rff rfi rfm rfp rfr rfs rie rif rii rim rip rir ris rme rmf rmi rmm rmp rmr rms rpe rpf rpi rpm rpp rpr rps rrf rri rrm rrp rrr rrs rse rsf rsi rsm rsp rsr rss se- see sef sei sem sep ser ses sfe sff sfi sfm sfp sfr sfs sie sif sii sim sip sir sis sme smf smi smm smp smr sms spe spf spi spm spp spr sps sr- sre srf sri srm srp srr srs ss- sse ssf ssi ssm ssp ssr sss