fours ofurs fuors ufors oufrs uofrs forus ofrus frous rfous orfus rofus furos ufros fruos rfuos urfos rufos ourfs uorfs orufs roufs urofs ruofs fousr ofusr fuosr ufosr oufsr uofsr fosur ofsur fsour sfour osfur sofur fusor ufsor fsuor sfuor usfor sufor ousfr uosfr osufr soufr usofr suofr forsu ofrsu frosu rfosu orfsu rofsu fosru ofsru fsoru sforu osfru sofru frsou rfsou fsrou sfrou rsfou srfou orsfu rosfu osrfu sorfu rsofu srofu furso ufrso fruso rfuso urfso rufso fusro ufsro fsuro sfuro usfro sufro frsuo rfsuo fsruo sfruo rsfuo srfuo ursfo rusfo usrfo surfo rsufo srufo oursf uorsf orusf rousf urosf ruosf ousrf uosrf osurf sourf usorf suorf orsuf rosuf osruf soruf rsouf srouf ursof rusof usrof surof rsuof sruof
Note: these 'words' (valid or invalid) are all the permutations of the word fours. These words are obtained by scrambling the letters in fours.