groof rgoof gorof ogrof rogof orgof groof rgoof gorof ogrof rogof orgof goorf ogorf goorf ogorf oogrf oogrf roogf orogf roogf orogf oorgf oorgf grofo rgofo gorfo ogrfo rogfo orgfo grfoo rgfoo gfroo fgroo rfgoo frgoo gofro ogfro gforo fgoro ofgro fogro rofgo orfgo rfogo frogo ofrgo forgo grofo rgofo gorfo ogrfo rogfo orgfo grfoo rgfoo gfroo fgroo rfgoo frgoo gofro ogfro gforo fgoro ofgro fogro rofgo orfgo rfogo frogo ofrgo forgo goofr ogofr goofr ogofr oogfr oogfr gofor ogfor gfoor fgoor ofgor fogor gofor ogfor gfoor fgoor ofgor fogor oofgr oofgr ofogr foogr ofogr foogr roofg orofg roofg orofg oorfg oorfg rofog orfog rfoog froog ofrog forog rofog orfog rfoog froog ofrog forog oofrg oofrg oforg foorg oforg foorg
Note: these 'words' (valid or invalid) are all the permutations of the word groof. These words are obtained by scrambling the letters in groof.