tcfis ctfis tfcis ftcis cftis fctis tcifs ctifs ticfs itcfs citfs ictfs tfics ftics tifcs itfcs fitcs iftcs cfits fcits cifts icfts ficts ifcts tcfsi ctfsi tfcsi ftcsi cftsi fctsi tcsfi ctsfi tscfi stcfi cstfi sctfi tfsci ftsci tsfci stfci fstci sftci cfsti fcsti csfti scfti fscti sfcti tcisf ctisf ticsf itcsf citsf ictsf tcsif ctsif tscif stcif cstif sctif tiscf itscf tsicf sticf istcf sitcf cistf icstf csitf scitf isctf sictf tfisc ftisc tifsc itfsc fitsc iftsc tfsic ftsic tsfic stfic fstic sftic tisfc itsfc tsifc stifc istfc sitfc fistc ifstc fsitc sfitc isftc siftc cfist fcist cifst icfst ficst ifcst cfsit fcsit csfit scfit fscit sfcit cisft icsft csift scift iscft sicft fisct ifsct fsict sfict isfct sifct
Note: these 'words' (valid or invalid) are all the permutations of the word tcfis. These words are obtained by scrambling the letters in tcfis.