-ol eee eef eel eeo eet eex ef- efe eff efl efo eft efx ele elf ell elo elt elx eo- eoe eof eol eoo eot ete etf etl eto ett etx ex- exe exl exo ext exx fee fef fel feo fet fex ffe fff ffl ffo fft ffx fle flf fll flo flt flx foe fof fol foo fot fox fte ftf ftl fto ftt ftx fxe fxt fxx lee lef lel leo let lex lfe lff lfl lfo lft lfx lle llf lll llo llt loe lof lol loo lot lox lte ltf ltl lto ltt ltx lxo lxx oee oef oel oeo oet oex of- ofe off ofl ofo oft ofx ole olf oll olo olt oo- oof ool ooo oot oox ot- ote otf otl oto ott ox- oxf oxo oxt oxx t-x te- tee tef tel teo tet tex tfe tff tfl tfo tft tfx tle tlf tll tlo tlt tlx to- toe tof tol too tot tox tte ttf ttl tto ttt ttx txe txf txl txt xee xel xet xex xfe xfl xft xfx xlf xlt xof xoo xot xox xtf xtx xxl xxo xxx