eee eef eem eep ef- efe eff efi efm efp eie eif eii eim eip em- eme emf emi emm emp ep- epe epf epi epm epp fee fef fei fem fep ffe fff ffi ffm ffp fie fif fii fim fip fme fmf fmi fmm fmp fpe fpi fpm fpp i-f ie- iee ief iei iem iep ife iff ifi ifm ifp iie iif iii iim iip im- ime imf imi imm imp ipe ipf ipi ipm ipp m-f mee mef mei mem mep mfe mff mfi mfm mfp mi- mie mif mii mim mip mme mmf mmi mmm mmp mpe mpf mpi mpm mpp p-p pee pef pei pem pep pfe pff pfi pfm pfp pie pif pii pim pip pme pmf pmi pmm pmp ppe ppf ppi ppm ppp