uptil putil utpil tupil ptuil tpuil upitl puitl uiptl iuptl piutl iputl utipl tuipl uitpl iutpl tiupl itupl ptiul tpiul pitul iptul tipul itpul uptli putli utpli tupli ptuli tpuli uplti pulti ulpti lupti pluti lputi utlpi tulpi ultpi lutpi tlupi ltupi ptlui tplui pltui lptui tlpui ltpui upilt puilt uiplt iuplt piult ipult uplit pulit ulpit lupit pluit lpuit uilpt iulpt ulipt luipt ilupt liupt pilut iplut pliut lpiut ilput liput utilp tuilp uitlp iutlp tiulp itulp utlip tulip ultip lutip tluip ltuip uiltp iultp ulitp luitp ilutp liutp tilup itlup tliup ltiup iltup litup ptilu tpilu pitlu iptlu tiplu itplu ptliu tpliu pltiu lptiu tlpiu ltpiu piltu ipltu plitu lpitu ilptu liptu tilpu itlpu tlipu ltipu iltpu litpu
Note: these 'words' (valid or invalid) are all the permutations of the word uptil. These words are obtained by scrambling the letters in uptil.