mutrr umtrr mturr tmurr utmrr tumrr murtr umrtr mrutr rmutr urmtr rumtr mtrur tmrur mrtur rmtur trmur rtmur utrmr turmr urtmr rutmr trumr rtumr mutrr umtrr mturr tmurr utmrr tumrr murtr umrtr mrutr rmutr urmtr rumtr mtrur tmrur mrtur rmtur trmur rtmur utrmr turmr urtmr rutmr trumr rtumr murrt umrrt mrurt rmurt urmrt rumrt murrt umrrt mrurt rmurt urmrt rumrt mrrut rmrut mrrut rmrut rrmut rrmut urrmt rurmt urrmt rurmt rrumt rrumt mtrru tmrru mrtru rmtru trmru rtmru mtrru tmrru mrtru rmtru trmru rtmru mrrtu rmrtu mrrtu rmrtu rrmtu rrmtu trrmu rtrmu trrmu rtrmu rrtmu rrtmu utrrm turrm urtrm rutrm trurm rturm utrrm turrm urtrm rutrm trurm rturm urrtm rurtm urrtm rurtm rrutm rrutm trrum rtrum trrum rtrum rrtum rrtum
Note: these 'words' (valid or invalid) are all the permutations of the word mutrr. These words are obtained by scrambling the letters in mutrr.