river irver rvier vrier ivrer virer rievr irevr reivr erivr iervr eirvr rveir vreir revir ervir verir evrir iverr vierr ievrr eivrr veirr evirr rivre irvre rvire vrire ivrre virre rirve irrve rrive rrive irrve rirve rvrie vrrie rrvie rrvie vrrie rvrie ivrre virre irvre rivre vrire rvire rierv irerv reirv erirv ierrv eirrv rirev irrev rriev rriev irrev rirev reriv erriv rreiv rreiv erriv reriv ierrv eirrv irerv rierv erirv reirv rveri vreri revri ervri verri evrri rvrei vrrei rrvei rrvei vrrei rvrei rervi errvi rrevi rrevi errvi rervi verri evrri vreri rveri ervri revri iverr vierr ievrr eivrr veirr evirr ivrer virer irver river vrier rvier iervr eirvr irevr rievr erivr reivr verir evrir vreir rveir ervir revir
Note: these 'words' (valid or invalid) are all the permutations of the word river. These words are obtained by scrambling the letters in river.