-er eee eef eel eer ees eet eex ef- efe eff efi efl efr efs eft efx eie eif eii eil eir eis eit eix ele elf eli ell elr els elt elx ere erf eri erl err ers ert es- ese esf esi esl esr ess est esx ete etf eti etl etr ets ett etx ex- exe exi exl exr exs ext exx fee fef fei fel fer fes fet fex ffe fff ffi ffl ffr ffs fft ffx fie fif fii fil fir fis fit fix fle flf fli fll flr fls flt flx fre frf fri frl frr frs frt fse fsf fsi fsl fsr fss fst fsx fte ftf fti ftl ftr fts ftt ftx fxe fxi fxr fxs fxt fxx i-f ie- iee ief iei iel ier ies iet iex ife iff ifi ifl ifr ifs ift ifx iie iif iii iil iir iis iit iix il- ile ilf ili ill ilr ils ilt ilx ir- ire irf iri irl irr irs irt irx is- ise isf isi isl isr iss ist ite itf iti itl its itt itx ixe ixi ixl lee lef lei lel ler les let lex lfe lff lfi lfl lfr lfs lft lfx lie lif lii lil lir lis lit lix lle llf lli lll llr lls llt lrf lri lrr lrs lrt lse lsf lsi lsl lsr lss lst lte ltf lti ltl ltr lts ltt ltx lxi lxr lxx re- ree ref rei rel rer res ret rex rfe rff rfi rfl rfr rfs rft rie rif rii ril rir ris rit rix rle rlf rli rll rlr rls rlt rrf rri rrl rrr rrs rrt rse rsf rsi rsl rsr rss rst rsx rte rtf rti rtl rtr rts rtt rtx rxr rxs se- see sef sei sel ser ses set sex sfe sff sfi sfl sfr sfs sft sfx sie sif sii sil sir sis sit six sle slf sli sll slr sls slt slx sr- sre srf sri srl srr srs srt srx ss- sse ssf ssi ssl ssr sss sst ssx ste stf sti stl str sts stt stx sxi sxl sxs sxt t-x te- tee tef tei tel ter tes tet tex tfe tff tfi tfl tfr tfs tft tfx tie tif tii til tir tis tit tix tle tlf tli tll tlr tls tlt tlx tre trf tri trl trr trs trt trx tse tsf tsi tsl tsr tss tst tsx tte ttf tti ttl ttr tts ttt ttx txe txf txi txl txs txt xee xel xer xes xet xex xfe xfl xfs xft xfx xie xii xis xit xix xlf xli xlr xls xlt xrf xrt xrx xsi xsl xss xst xtf xti xtr xts xtx xxi xxl xxx