brain rbain barin abrin rabin arbin brian rbian biran ibran riban irban bairn abirn biarn ibarn aibrn iabrn raibn aribn riabn irabn airbn iarbn brani rbani barni abrni rabni arbni brnai rbnai bnrai nbrai rnbai nrbai banri abnri bnari nbari anbri nabri ranbi arnbi rnabi nrabi anrbi narbi brina rbina birna ibrna ribna irbna brnia rbnia bnria nbria rnbia nrbia binra ibnra bnira nbira inbra nibra rinba irnba rniba nriba inrba nirba bainr abinr bianr ibanr aibnr iabnr banir abnir bnair nbair anbir nabir binar ibnar bniar nbiar inbar nibar ainbr ianbr anibr naibr inabr niabr rainb arinb rianb iranb airnb iarnb ranib arnib rnaib nraib anrib narib rinab irnab rniab nriab inrab nirab ainrb ianrb anirb nairb inarb niarb
Note: these 'words' (valid or invalid) are all the permutations of the word brain. These words are obtained by scrambling the letters in brain.