trull rtull turll utrll rutll urtll trlul rtlul tlrul ltrul rltul lrtul tulrl utlrl tlurl lturl ultrl lutrl rultl urltl rlutl lrutl ulrtl lurtl trull rtull turll utrll rutll urtll trlul rtlul tlrul ltrul rltul lrtul tulrl utlrl tlurl lturl ultrl lutrl rultl urltl rlutl lrutl ulrtl lurtl trllu rtllu tlrlu ltrlu rltlu lrtlu trllu rtllu tlrlu ltrlu rltlu lrtlu tllru ltlru tllru ltlru lltru lltru rlltu lrltu rlltu lrltu llrtu llrtu tullr utllr tlulr ltulr ultlr lutlr tullr utllr tlulr ltulr ultlr lutlr tllur ltlur tllur ltlur lltur lltur ulltr lultr ulltr lultr llutr llutr rullt urllt rlult lrult ulrlt lurlt rullt urllt rlult lrult ulrlt lurlt rllut lrlut rllut lrlut llrut llrut ullrt lulrt ullrt lulrt llurt llurt
Note: these 'words' (valid or invalid) are all the permutations of the word trull. These words are obtained by scrambling the letters in trull.