Walt Disney's first job in automation was with the Kansas City Film Ad Company in 1920, when he worked on stop-action commercial animation with cutout paper puppets that had movable joints. He and his brother Roy moved to Los Angeles in 1923 and by 1926 they were successful enough to open the Walt Disney Studio. Mickey Mouse was introduced two years later in Steamboat Willie. By 1933 when he was thirty-one the idea of making the first animated full-length feature film, Snow White and the Seven Dwarfs, crystallized in Disney's mind, although it would be another four years before the film premiered on December 21, 1937. He chose the Brothers Grimm fable as one that was "known and beloved in practically every country in the world."