ruder urder rduer druer udrer durer ruedr uredr reudr erudr uerdr eurdr rdeur dreur redur erdur derur edrur uderr duerr uedrr eudrr deurr edurr rudre urdre rdure drure udrre durre rurde urrde rrude rrude urrde rurde rdrue drrue rrdue rrdue drrue rdrue udrre durre urdre rudre drure rdure ruerd urerd reurd erurd uerrd eurrd rured urred rrued rrued urred rured rerud errud rreud rreud errud rerud uerrd eurrd urerd ruerd erurd reurd rderu dreru redru erdru derru edrru rdreu drreu rrdeu rrdeu drreu rdreu rerdu errdu rredu rredu errdu rerdu derru edrru dreru rderu erdru redru uderr duerr uedrr eudrr deurr edurr udrer durer urder ruder druer rduer uerdr eurdr uredr ruedr erudr reudr derur edrur dreur rdeur erdur redur
Note: these 'words' (valid or invalid) are all the permutations of the word ruder. These words are obtained by scrambling the letters in ruder.