trduc rtduc tdruc dtruc rdtuc drtuc trudc rtudc turdc utrdc rutdc urtdc tdurc dturc tudrc utdrc dutrc udtrc rdutc drutc rudtc urdtc durtc udrtc trdcu rtdcu tdrcu dtrcu rdtcu drtcu trcdu rtcdu tcrdu ctrdu rctdu crtdu tdcru dtcru tcdru ctdru dctru cdtru rdctu drctu rcdtu crdtu dcrtu cdrtu trucd rtucd turcd utrcd rutcd urtcd trcud rtcud tcrud ctrud rctud crtud tucrd utcrd tcurd cturd uctrd cutrd ructd urctd rcutd crutd ucrtd curtd tducr dtucr tudcr utdcr dutcr udtcr tdcur dtcur tcdur ctdur dctur cdtur tucdr utcdr tcudr ctudr uctdr cutdr ductr udctr dcutr cdutr ucdtr cudtr rduct druct rudct urdct durct udrct rdcut drcut rcdut crdut dcrut cdrut rucdt urcdt rcudt crudt ucrdt curdt ducrt udcrt dcurt cdurt ucdrt cudrt
Note: these 'words' (valid or invalid) are all the permutations of the word trduc. These words are obtained by scrambling the letters in trduc.