-er eee eef eek eer ees eet ef- efe eff efi efr efs eft eie eif eii eik eir eis eit eke ekf eki ekr eks ekt ere erf eri erk err ers ert es- ese esf esi esk esr ess est ete etf eti etk etr ets ett fee fef fei fek fer fes fet ffe fff ffi ffk ffr ffs fft fie fif fii fik fir fis fit fkf fki fkk fkt fre frf fri frk frr frs frt fse fsf fsi fsk fsr fss fst fte ftf fti ftk ftr fts ftt i-f ie- iee ief iei iek ier ies iet ife iff ifi ifr ifs ift iie iif iii iir iis iit ike ikf iki ikk ikr iks ikt ir- ire irf iri irk irr irs irt is- ise isf isi isk isr iss ist ite itf iti itk its itt k-t ke- kee kef kei kek ker kes ket kff kfi kfs kie kif kii kik kir kis kit kke kki kkk kkr kks kkt krf kri krk krr krs krt kse ksf ksi ksk ksr kss kst kte ktf ktk ktr kts ktt re- ree ref rei rek rer res ret rfe rff rfi rfk rfr rfs rft rie rif rii rik rir ris rit rke rkf rkk rks rkt rrf rri rrk rrr rrs rrt rse rsf rsi rsk rsr rss rst rte rtf rti rtk rtr rts rtt se- see sef sei sek ser ses set sfe sff sfi sfk sfr sfs sft sie sif sii sik sir sis sit sk- ske skf ski skk skr sks skt sr- sre srf sri srk srr srs srt ss- sse ssf ssi ssk ssr sss sst ste stf sti stk str sts stt te- tee tef tei tek ter tes tet tfe tff tfi tfk tfr tfs tft tie tif tii tik tir tis tit tke tkk tkr tks tkt tre trf tri trk trr trs trt tse tsf tsi tsk tsr tss tst tte ttf tti ttk ttr tts ttt