nandu anndu nnadu nnadu anndu nandu nadnu andnu ndanu dnanu adnnu dannu nndau nndau ndnau dnnau ndnau dnnau andnu nadnu adnnu dannu ndanu dnanu nanud annud nnaud nnaud annud nanud naund anund nuand unand aunnd uannd nnuad nnuad nunad unnad nunad unnad anund naund aunnd uannd nuand unand nadun andun ndaun dnaun adnun danun naudn anudn nuadn unadn aundn uandn nduan dnuan nudan undan dunan udnan adunn daunn audnn uadnn duann udann nndua nndua ndnua dnnua ndnua dnnua nnuda nnuda nunda unnda nunda unnda nduna dnuna nudna undna dunna udnna nduna dnuna nudna undna dunna udnna andun nadun adnun danun ndaun dnaun anudn naudn aundn uandn nuadn unadn adunn daunn audnn uadnn duann udann nduan dnuan nudan undan dunan udnan
Note: these 'words' (valid or invalid) are all the permutations of the word nandu. These words are obtained by scrambling the letters in nandu.