fedex efdex fdeex dfeex edfex defex feedx efedx feedx efedx eefdx eefdx fdeex dfeex fedex efdex defex edfex edefx deefx eedfx eedfx deefx edefx fedxe efdxe fdexe dfexe edfxe defxe fexde efxde fxede xfede exfde xefde fdxee dfxee fxdee xfdee dxfee xdfee edxfe dexfe exdfe xedfe dxefe xdefe feexd efexd feexd efexd eefxd eefxd fexed efxed fxeed xfeed exfed xefed fexed efxed fxeed xfeed exfed xefed eexfd eexfd exefd xeefd exefd xeefd fdexe dfexe fedxe efdxe defxe edfxe fdxee dfxee fxdee xfdee dxfee xdfee fexde efxde fxede xfede exfde xefde dexfe edxfe dxefe xdefe exdfe xedfe edexf deexf eedxf eedxf deexf edexf edxef dexef exdef xedef dxeef xdeef eexdf eexdf exedf xeedf exedf xeedf dexef edxef dxeef xdeef exdef xedef
Note: these 'words' (valid or invalid) are all the permutations of the word fedex. These words are obtained by scrambling the letters in fedex.