unpin nupin upnin punin npuin pnuin unipn nuipn uinpn iunpn niupn inupn upinn puinn uipnn iupnn piunn ipunn npiun pniun nipun inpun pinun ipnun unpni nupni upnni punni npuni pnuni unnpi nunpi unnpi nunpi nnupi nnupi upnni punni unpni nupni pnuni npuni npnui pnnui nnpui nnpui pnnui npnui uninp nuinp uinnp iunnp niunp inunp unnip nunip unnip nunip nnuip nnuip uinnp iunnp uninp nuinp inunp niunp ninup innup nniup nniup innup ninup upinn puinn uipnn iupnn piunn ipunn upnin punin unpin nupin pnuin npuin uinpn iunpn unipn nuipn inupn niupn pinun ipnun pniun npiun inpun nipun npinu pninu nipnu inpnu pinnu ipnnu npniu pnniu nnpiu nnpiu pnniu npniu ninpu innpu nnipu nnipu innpu ninpu pinnu ipnnu pninu npinu inpnu nipnu
Note: these 'words' (valid or invalid) are all the permutations of the word unpin. These words are obtained by scrambling the letters in unpin.