trigs rtigs tirgs itrgs ritgs irtgs trgis rtgis tgris gtris rgtis grtis tigrs itgrs tgirs gtirs igtrs gitrs rigts irgts rgits grits igrts girts trisg rtisg tirsg itrsg ritsg irtsg trsig rtsig tsrig strig rstig srtig tisrg itsrg tsirg stirg istrg sitrg ristg irstg rsitg sritg isrtg sirtg trgsi rtgsi tgrsi gtrsi rgtsi grtsi trsgi rtsgi tsrgi strgi rstgi srtgi tgsri gtsri tsgri stgri gstri sgtri rgsti grsti rsgti srgti gsrti sgrti tigsr itgsr tgisr gtisr igtsr gitsr tisgr itsgr tsigr stigr istgr sitgr tgsir gtsir tsgir stgir gstir sgtir igstr gistr isgtr sigtr gsitr sgitr rigst irgst rgist grist igrst girst risgt irsgt rsigt srigt isrgt sirgt rgsit grsit rsgit srgit gsrit sgrit igsrt gisrt isgrt sigrt gsirt sgirt
Note: these 'words' (valid or invalid) are all the permutations of the word trigs. These words are obtained by scrambling the letters in trigs.