Task: Question Generation
Input (English): The band have released a total of eighteen number one albums, eighteen number one singles, and ten number one DVDs worldwide, making them one of the world's best-selling music artists. Queen have sold over 150 million records, with some estimates in excess of 300 million records worldwide, including 34.5 million albums in the US as of 2004. Inducted into the Rock and Roll Hall of Fame in 2001, the band is the only group in which every member has composed more than one chart-topping single, and all four members were inducted into the Songwriters Hall of Fame in 2003. In 2009, "We Will Rock You" and "We Are the Champions" were inducted into the Grammy Hall of Fame, and the latter was voted the world's favourite song in a global music poll.
Output (English): How many number one DVD's has Queen released?