Task: Question Answering
Input (English): Passage: Rolling Stone described "Imagine" as Lennon's "greatest musical gift to the world", praising "the serene melody; the pillowy chord progression; [and] that beckoning, four-note [piano] figure". Robert Christgau called it "both a hymn for the Movement and a love song for his wife, celebrating a Yokoism and a Marcusianism simultaneously". Included in several song polls, in 1999, BMI named it one of the top 100 most-performed songs of the 20th century. Also that year, it received the Grammy Hall of Fame Award and an induction into the Rock and Roll Hall of Fame's 500 Songs that Shaped Rock and Roll. "Imagine" ranked number 23 in the list of best-selling singles of all time in the UK, in 2000. In 2002, a UK survey conducted by the Guinness World Records British Hit Singles Book ranked it the second best single of all time behind Queen's "Bohemian Rhapsody". Gold Radio ranked the song number three on its "Gold's greatest 1000 hits" list.Rolling Stone ranked "Imagine" number three on its list of "The 500 Greatest Songs of All Time", describing it as "an enduring hymn of solace and promise that has carried us through extreme grief, from the shock of Lennon's own death in 1980 to the unspeakable horror of September 11th. It is now impossible to imagine a world without 'Imagine', and we need it more than he ever dreamed." Despite that sentiment, Clear Channel Communications (now known today as iHeartMedia) included the song on its post-9/11 "do not play" list.On 1 January 2005, the Canadian Broadcasting Corporation named "Imagine" the greatest song in the past 100 years as voted by listeners on the show 50 Tracks. The song ranked number 30 on the Recording Industry Association of America's list of the 365 Songs of the Century bearing the most historical significance. Virgin Radio conducted a UK favourite song survey in December 2005, and listeners voted "Imagine" number one. Australians selected it the greatest song of all time on the Nine Network's 20 to 1 countdown show on 12 September 2006. They voted it eleventh in the youth radio network Triple J's Hottest 100 Of All Time on 11 July 2009. 
Question: What was the last name of the person who wrote Imagine as a love song for his wife?
Output (English): Lennon.