frist rfist first ifrst rifst irfst frsit rfsit fsrit sfrit rsfit srfit fisrt ifsrt fsirt sfirt isfrt sifrt risft irsft rsift srift isrft sirft frits rfits firts ifrts rifts irfts frtis rftis ftris tfris rtfis trfis fitrs iftrs ftirs tfirs itfrs tifrs ritfs irtfs rtifs trifs itrfs tirfs frsti rfsti fsrti sfrti rsfti srfti frtsi rftsi ftrsi tfrsi rtfsi trfsi fstri sftri ftsri tfsri stfri tsfri rstfi srtfi rtsfi trsfi strfi tsrfi fistr ifstr fsitr sfitr isftr siftr fitsr iftsr ftisr tfisr itfsr tifsr fstir sftir ftsir tfsir stfir tsfir istfr sitfr itsfr tisfr stifr tsifr ristf irstf rsitf sritf isrtf sirtf ritsf irtsf rtisf trisf itrsf tirsf rstif srtif rtsif trsif strif tsrif istrf sitrf itsrf tisrf stirf tsirf
Note: these 'words' (valid or invalid) are all the permutations of the word frist. These words are obtained by scrambling the letters in frist.