fnbsi nfbsi fbnsi bfnsi nbfsi bnfsi fnsbi nfsbi fsnbi sfnbi nsfbi snfbi fbsni bfsni fsbni sfbni bsfni sbfni nbsfi bnsfi nsbfi snbfi bsnfi sbnfi fnbis nfbis fbnis bfnis nbfis bnfis fnibs nfibs finbs ifnbs nifbs infbs fbins bfins fibns ifbns bifns ibfns nbifs bnifs nibfs inbfs binfs ibnfs fnsib nfsib fsnib sfnib nsfib snfib fnisb nfisb finsb ifnsb nifsb infsb fsinb sfinb fisnb ifsnb sifnb isfnb nsifb snifb nisfb insfb sinfb isnfb fbsin bfsin fsbin sfbin bsfin sbfin fbisn bfisn fibsn ifbsn bifsn ibfsn fsibn sfibn fisbn ifsbn sifbn isfbn bsifn sbifn bisfn ibsfn sibfn isbfn nbsif bnsif nsbif snbif bsnif sbnif nbisf bnisf nibsf inbsf binsf ibnsf nsibf snibf nisbf insbf sinbf isnbf bsinf sbinf bisnf ibsnf sibnf isbnf
Note: these 'words' (valid or invalid) are all the permutations of the word fnbsi. These words are obtained by scrambling the letters in fnbsi.