uacds aucds ucads cuads acuds cauds uadcs audcs udacs duacs aducs daucs ucdas cudas udcas ducas cduas dcuas acdus cadus adcus dacus cdaus dcaus uacsd aucsd ucasd cuasd acusd causd uascd auscd usacd suacd asucd saucd ucsad cusad uscad sucad csuad scuad acsud casud ascud sacud csaud scaud uadsc audsc udasc duasc adusc dausc uasdc ausdc usadc suadc asudc saudc udsac dusac usdac sudac dsuac sduac adsuc dasuc asduc saduc dsauc sdauc ucdsa cudsa udcsa ducsa cdusa dcusa ucsda cusda uscda sucda csuda scuda udsca dusca usdca sudca dsuca sduca cdsua dcsua csdua scdua dscua sdcua acdsu cadsu adcsu dacsu cdasu dcasu acsdu casdu ascdu sacdu csadu scadu adscu dascu asdcu sadcu dsacu sdacu cdsau dcsau csdau scdau dscau sdcau
Note: these 'words' (valid or invalid) are all the permutations of the word uacds. These words are obtained by scrambling the letters in uacds.