dukas udkas dkuas kduas ukdas kudas duaks udaks dauks aduks uadks audks dkaus kdaus dakus adkus kadus akdus ukads kuads uakds aukds kauds akuds duksa udksa dkusa kdusa ukdsa kudsa duska udska dsuka sduka usdka sudka dksua kdsua dskua sdkua ksdua skdua uksda kusda uskda sukda ksuda skuda duask udask dausk adusk uadsk audsk dusak udsak dsuak sduak usdak sudak dasuk adsuk dsauk sdauk asduk saduk uasdk ausdk usadk suadk asudk saudk dkasu kdasu daksu adksu kadsu akdsu dksau kdsau dskau sdkau ksdau skdau dasku adsku dsaku sdaku asdku sadku kasdu aksdu ksadu skadu askdu sakdu ukasd kuasd uaksd auksd kausd akusd uksad kusad uskad sukad ksuad skuad uaskd auskd usakd suakd asukd saukd kasud aksud ksaud skaud askud sakud
Note: these 'words' (valid or invalid) are all the permutations of the word dukas. These words are obtained by scrambling the letters in dukas.