focus ofcus fcous cfous ocfus cofus foucs ofucs fuocs ufocs oufcs uofcs fcuos cfuos fucos ufcos cufos ucfos ocufs coufs oucfs uocfs cuofs ucofs focsu ofcsu fcosu cfosu ocfsu cofsu foscu ofscu fsocu sfocu osfcu sofcu fcsou cfsou fscou sfcou csfou scfou ocsfu cosfu oscfu socfu csofu scofu fousc ofusc fuosc ufosc oufsc uofsc fosuc ofsuc fsouc sfouc osfuc sofuc fusoc ufsoc fsuoc sfuoc usfoc sufoc ousfc uosfc osufc soufc usofc suofc fcuso cfuso fucso ufcso cufso ucfso fcsuo cfsuo fscuo sfcuo csfuo scfuo fusco ufsco fsuco sfuco usfco sufco cusfo ucsfo csufo scufo uscfo sucfo ocusf cousf oucsf uocsf cuosf ucosf ocsuf cosuf oscuf socuf csouf scouf ouscf uoscf osucf soucf usocf suocf cusof ucsof csuof scuof uscof sucof
Note: these 'words' (valid or invalid) are all the permutations of the word focus. These words are obtained by scrambling the letters in focus.