penni epnni pneni npeni enpni nepni penni epnni pneni npeni enpni nepni pnnei npnei pnnei npnei nnpei nnpei ennpi nenpi ennpi nenpi nnepi nnepi penin epnin pnein npein enpin nepin peinn epinn pienn ipenn eipnn iepnn pnien npien pinen ipnen nipen inpen enipn neipn einpn ienpn niepn inepn penin epnin pnein npein enpin nepin peinn epinn pienn ipenn eipnn iepnn pnien npien pinen ipnen nipen inpen enipn neipn einpn ienpn niepn inepn pnnie npnie pnnie npnie nnpie nnpie pnine npine pinne ipnne nipne inpne pnine npine pinne ipnne nipne inpne nnipe nnipe ninpe innpe ninpe innpe ennip nenip ennip nenip nneip nneip eninp neinp einnp iennp nienp inenp eninp neinp einnp iennp nienp inenp nniep nniep ninep innep ninep innep
Note: these 'words' (valid or invalid) are all the permutations of the word penni. These words are obtained by scrambling the letters in penni.