rgpn grpn rpgn prgn gprn pgrn rgnp grnp rngp nrgp gnrp ngrp rpng prng rnpg nrpg pnrg nprg gpnr pgnr gnpr ngpr pngr npgr
Note: these 'words' (valid or invalid) are all the permutations of the word rgpn. These words are obtained by scrambling the letters in rgpn.