usotb suotb uostb oustb soutb osutb ustob sutob utsob tusob stuob tsuob uotsb outsb utosb tuosb otusb tousb sotub ostub stoub tsoub otsub tosub usobt suobt uosbt ousbt soubt osubt usbot subot ubsot busot sbuot bsuot uobst oubst ubost buost obust boust sobut osbut sbout bsout obsut bosut ustbo sutbo utsbo tusbo stubo tsubo usbto subto ubsto busto sbuto bsuto utbso tubso ubtso butso tbuso btuso stbuo tsbuo sbtuo bstuo tbsuo btsuo uotbs outbs utobs tuobs otubs toubs uobts oubts ubots buots obuts bouts utbos tubos ubtos butos tbuos btuos otbus tobus obtus botus tbous btous sotbu ostbu stobu tsobu otsbu tosbu sobtu osbtu sbotu bsotu obstu bostu stbou tsbou sbtou bstou tbsou btsou otbsu tobsu obtsu botsu tbosu btosu
Note: these 'words' (valid or invalid) are all the permutations of the word usotb. These words are obtained by scrambling the letters in usotb.