flees lfees feles efles lefes elfes flees lfees feles efles lefes elfes feels efels feels efels eefls eefls leefs elefs leefs elefs eelfs eelfs flese lfese felse eflse lefse elfse flsee lfsee fslee sflee lsfee slfee fesle efsle fsele sfele esfle sefle lesfe elsfe lsefe slefe eslfe selfe flese lfese felse eflse lefse elfse flsee lfsee fslee sflee lsfee slfee fesle efsle fsele sfele esfle sefle lesfe elsfe lsefe slefe eslfe selfe feesl efesl feesl efesl eefsl eefsl fesel efsel fseel sfeel esfel sefel fesel efsel fseel sfeel esfel sefel eesfl eesfl esefl seefl esefl seefl leesf elesf leesf elesf eelsf eelsf lesef elsef lseef sleef eslef selef lesef elsef lseef sleef eslef selef eeslf eeslf eself seelf eself seelf
Note: these 'words' (valid or invalid) are all the permutations of the word flees. These words are obtained by scrambling the letters in flees.