rungs urngs rnugs nrugs unrgs nurgs rugns urgns rguns gruns ugrns gurns rngus nrgus rgnus grnus ngrus gnrus ungrs nugrs ugnrs gunrs ngurs gnurs runsg urnsg rnusg nrusg unrsg nursg rusng ursng rsung srung usrng surng rnsug nrsug rsnug srnug nsrug snrug unsrg nusrg usnrg sunrg nsurg snurg rugsn urgsn rgusn grusn ugrsn gursn rusgn ursgn rsugn srugn usrgn surgn rgsun grsun rsgun srgun gsrun sgrun ugsrn gusrn usgrn sugrn gsurn sgurn rngsu nrgsu rgnsu grnsu ngrsu gnrsu rnsgu nrsgu rsngu srngu nsrgu snrgu rgsnu grsnu rsgnu srgnu gsrnu sgrnu ngsru gnsru nsgru sngru gsnru sgnru ungsr nugsr ugnsr gunsr ngusr gnusr unsgr nusgr usngr sungr nsugr snugr ugsnr gusnr usgnr sugnr gsunr sgunr ngsur gnsur nsgur sngur gsnur sgnur
Note: these 'words' (valid or invalid) are all the permutations of the word rungs. These words are obtained by scrambling the letters in rungs.