flues lfues fules ufles lufes ulfes fleus lfeus felus eflus lefus elfus fuels ufels feuls efuls uefls eufls luefs ulefs leufs elufs uelfs eulfs fluse lfuse fulse uflse lufse ulfse flsue lfsue fslue sflue lsfue slfue fusle ufsle fsule sfule usfle sufle lusfe ulsfe lsufe slufe uslfe sulfe flesu lfesu felsu eflsu lefsu elfsu flseu lfseu fsleu sfleu lsfeu slfeu feslu efslu fselu sfelu esflu seflu lesfu elsfu lsefu slefu eslfu selfu fuesl ufesl feusl efusl uefsl eufsl fusel ufsel fsuel sfuel usfel sufel fesul efsul fseul sfeul esful seful uesfl eusfl usefl suefl esufl seufl luesf ulesf leusf elusf uelsf eulsf lusef ulsef lsuef sluef uslef sulef lesuf elsuf lseuf sleuf esluf seluf ueslf euslf uself suelf esulf seulf
Note: these 'words' (valid or invalid) are all the permutations of the word flues. These words are obtained by scrambling the letters in flues.