bunds ubnds bnuds nbuds unbds nubds budns ubdns bduns dbuns udbns dubns bndus nbdus bdnus dbnus ndbus dnbus undbs nudbs udnbs dunbs ndubs dnubs bunsd ubnsd bnusd nbusd unbsd nubsd busnd ubsnd bsund sbund usbnd subnd bnsud nbsud bsnud sbnud nsbud snbud unsbd nusbd usnbd sunbd nsubd snubd budsn ubdsn bdusn dbusn udbsn dubsn busdn ubsdn bsudn sbudn usbdn subdn bdsun dbsun bsdun sbdun dsbun sdbun udsbn dusbn usdbn sudbn dsubn sdubn bndsu nbdsu bdnsu dbnsu ndbsu dnbsu bnsdu nbsdu bsndu sbndu nsbdu snbdu bdsnu dbsnu bsdnu sbdnu dsbnu sdbnu ndsbu dnsbu nsdbu sndbu dsnbu sdnbu undsb nudsb udnsb dunsb ndusb dnusb unsdb nusdb usndb sundb nsudb snudb udsnb dusnb usdnb sudnb dsunb sdunb ndsub dnsub nsdub sndub dsnub sdnub
Note: these 'words' (valid or invalid) are all the permutations of the word bunds. These words are obtained by scrambling the letters in bunds.