prune rpune purne uprne rupne urpne prnue rpnue pnrue nprue rnpue nrpue punre upnre pnure npure unpre nupre runpe urnpe rnupe nrupe unrpe nurpe pruen rpuen puren upren rupen urpen preun rpeun perun eprun repun erpun puern upern peurn epurn ueprn euprn ruepn urepn reupn erupn uerpn eurpn prneu rpneu pnreu npreu rnpeu nrpeu prenu rpenu pernu eprnu repnu erpnu pneru nperu penru epnru nepru enpru rnepu nrepu renpu ernpu nerpu enrpu puner upner pnuer npuer unper nuper puenr upenr peunr epunr uepnr eupnr pneur npeur penur epnur nepur enpur unepr nuepr uenpr eunpr neupr enupr runep urnep rnuep nruep unrep nurep ruenp urenp reunp erunp uernp eurnp rneup nreup renup ernup nerup enrup unerp nuerp uenrp eunrp neurp enurp
Note: these 'words' (valid or invalid) are all the permutations of the word prune. These words are obtained by scrambling the letters in prune.