duper udper dpuer pduer upder puder duepr udepr deupr edupr uedpr eudpr dpeur pdeur depur edpur pedur epdur upedr puedr uepdr eupdr peudr epudr dupre udpre dpure pdure updre pudre durpe udrpe drupe rdupe urdpe rudpe dprue pdrue drpue rdpue prdue rpdue uprde purde urpde rupde prude rpude duerp uderp deurp edurp uedrp eudrp durep udrep druep rduep urdep rudep derup edrup dreup rdeup erdup redup uerdp eurdp uredp ruedp erudp reudp dperu pderu depru edpru pedru epdru dpreu pdreu drpeu rdpeu prdeu rpdeu derpu edrpu drepu rdepu erdpu redpu perdu eprdu predu rpedu erpdu repdu uperd puerd ueprd euprd peurd epurd upred pured urped ruped prued rpued uerpd eurpd urepd ruepd erupd reupd perud eprud preud rpeud erpud repud
Note: these 'words' (valid or invalid) are all the permutations of the word duper. These words are obtained by scrambling the letters in duper.