ducee udcee dcuee cduee ucdee cudee duece udece deuce educe uedce eudce dceue cdeue decue edcue cedue ecdue ucede cuede uecde eucde ceude ecude ducee udcee dcuee cduee ucdee cudee duece udece deuce educe uedce eudce dceue cdeue decue edcue cedue ecdue ucede cuede uecde eucde ceude ecude dueec udeec deuec eduec uedec eudec dueec udeec deuec eduec uedec eudec deeuc edeuc deeuc edeuc eeduc eeduc ueedc euedc ueedc euedc eeudc eeudc dceeu cdeeu deceu edceu cedeu ecdeu dceeu cdeeu deceu edceu cedeu ecdeu deecu edecu deecu edecu eedcu eedcu ceedu ecedu ceedu ecedu eecdu eecdu uceed cueed ueced euced ceued ecued uceed cueed ueced euced ceued ecued ueecd euecd ueecd euecd eeucd eeucd ceeud eceud ceeud eceud eecud eecud
Note: these 'words' (valid or invalid) are all the permutations of the word ducee. These words are obtained by scrambling the letters in ducee.