utfca tufca uftca futca tfuca ftuca utcfa tucfa uctfa cutfa tcufa ctufa ufcta fucta ucfta cufta fcuta cfuta tfcua ftcua tcfua ctfua fctua cftua utfac tufac uftac futac tfuac ftuac utafc tuafc uatfc autfc taufc atufc ufatc fuatc uaftc auftc fautc afutc tfauc ftauc tafuc atfuc fatuc aftuc utcaf tucaf uctaf cutaf tcuaf ctuaf utacf tuacf uatcf autcf taucf atucf ucatf cuatf uactf auctf cautf acutf tcauf ctauf tacuf atcuf catuf actuf ufcat fucat ucfat cufat fcuat cfuat ufact fuact uafct aufct fauct afuct ucaft cuaft uacft aucft cauft acuft fcaut cfaut facut afcut cafut acfut tfcau ftcau tcfau ctfau fctau cftau tfacu ftacu tafcu atfcu fatcu aftcu tcafu ctafu tacfu atcfu catfu actfu fcatu cfatu factu afctu caftu acftu
Note: these 'words' (valid or invalid) are all the permutations of the word utfca. These words are obtained by scrambling the letters in utfca.