Mars had an unsuccessful stint with Motown Records, but then signed with Atlantic in 2009. He became recognized as a solo artist after lending his vocals to the songs "Nothin' on You" by B.o.B, and "Billionaire" by Travie McCoy, which were international successes, and for which he co-wrote the hooks. His debut studio album, Doo-Wops & Hooligans (2010), was anchored by the U.S. Billboard Hot 100 chart-topping singles "Just the Way You Are" and "Grenade", as well as the number-five single "The Lazy Song". His second album, Unorthodox Jukebox, released in 2012, peaked at number one in the United States. The album spawned the international singles "Locked Out of Heaven", "When I Was Your Man" and "Treasure".