eee eef eep ees eet ef- efe eff efi efp efs eft eie eif eii eip eis eit ep- epe epf epi epp eps ept es- ese esf esi esp ess est ete etf eti etp ets ett fee fef fei fep fes fet ffe fff ffi ffp ffs fft fie fif fii fip fis fit fpe fpi fpp fps fpt fse fsf fsi fsp fss fst fte ftf fti ftp fts ftt i-f ie- iee ief iei iep ies iet ife iff ifi ifp ifs ift iie iif iii iip iis iit ipe ipf ipi ipp ips ipt is- ise isf isi isp iss ist ite itf iti itp its itt p-p pee pef pei pep pes pet pfe pff pfi pfp pfs pft pie pif pii pip pis pit ppe ppf ppi ppp pps ppt ps- pse psf psi psp pss pst pt- pte ptf pti ptp pts ptt se- see sef sei sep ses set sfe sff sfi sfp sfs sft sie sif sii sip sis sit spe spf spi spp sps spt ss- sse ssf ssi ssp sss sst ste stf sti stp sts stt te- tee tef tei tep tes tet tfe tff tfi tfp tfs tft tie tif tii tip tis tit tpe tpf tpi tpp tps tpt tse tsf tsi tsp tss tst tte ttf tti ttp tts ttt