hrubs rhubs hurbs uhrbs ruhbs urhbs hrbus rhbus hbrus bhrus rbhus brhus hubrs uhbrs hburs bhurs ubhrs buhrs rubhs urbhs rbuhs bruhs ubrhs burhs hrusb rhusb hursb uhrsb ruhsb urhsb hrsub rhsub hsrub shrub rshub srhub husrb uhsrb hsurb shurb ushrb suhrb rushb urshb rsuhb sruhb usrhb surhb hrbsu rhbsu hbrsu bhrsu rbhsu brhsu hrsbu rhsbu hsrbu shrbu rshbu srhbu hbsru bhsru hsbru shbru bshru sbhru rbshu brshu rsbhu srbhu bsrhu sbrhu hubsr uhbsr hbusr bhusr ubhsr buhsr husbr uhsbr hsubr shubr ushbr suhbr hbsur bhsur hsbur shbur bshur sbhur ubshr bushr usbhr subhr bsuhr sbuhr rubsh urbsh rbush brush ubrsh bursh rusbh ursbh rsubh srubh usrbh surbh rbsuh brsuh rsbuh srbuh bsruh sbruh ubsrh busrh usbrh subrh bsurh sburh
Note: these 'words' (valid or invalid) are all the permutations of the word hrubs. These words are obtained by scrambling the letters in hrubs.