Input (grade 10): Mengelberg died in 1951 just before the end of his sentence, thus never conducting the orchestra after 1945.
Output (grade 9): In 1945, after World War II had ended, Mengelberg was not allowed to conduct the orchestra because he had played to the Nazis. He was banned for six years from conducting them, but he died in 1951 just before the six years came to an end.