-er eee eef eep eer eet ef- efe eff efi efp efr eft eie eif eii eip eir eit ep- epe epf epi epp epr ept ere erf eri erp err ert ete etf eti etp etr ett fee fef fei fep fer fet ffe fff ffi ffp ffr fft fie fif fii fip fir fit fpe fpi fpp fpr fpt fre frf fri frp frr frt fte ftf fti ftp ftr ftt i-f ie- iee ief iei iep ier iet ife iff ifi ifp ifr ift iie iif iii iip iir iit ipe ipf ipi ipp ipr ipt ir- ire irf iri irp irr irt ite itf iti itp itt p-p pee pef pei pep per pet pfe pff pfi pfp pfr pft pie pif pii pip pir pit ppe ppf ppi ppp ppr ppt pre prf pri prp prr prt pt- pte ptf pti ptp ptr ptt re- ree ref rei rep rer ret rfe rff rfi rfp rfr rft rie rif rii rip rir rit rpe rpf rpi rpp rpr rpt rrf rri rrp rrr rrt rte rtf rti rtp rtr rtt te- tee tef tei tep ter tet tfe tff tfi tfp tfr tft tie tif tii tip tir tit tpe tpf tpi tpp tpr tpt tre trf tri trp trr trt tte ttf tti ttp ttr ttt