Question: Who was the brother of the United Artists Corporation founder?

full_context: Document 1: Desperate (film): Desperate is a 1947 suspense film noir directed by Anthony Mann and featuring Steve Brodie, Audrey Long, Raymond Burr, Douglas Fowley, William Challee and Jason Robards.
Document 2: Mr. Flip: Mr. Flip is a 1909 American silent comedy film made by Essanay Studios, directed by Gilbert M. 'Broncho Billy' Anderson and starring Ben Turpin. The film is about a man going to various locations in town where he flirts with the women, and they in turn get revenge on him, causing him to leave their establishment. This film is believed to have included the first cinematic instance of a comedian being hit in the face with a pie, later known as the Pie in the Face, when Ben Turpin was struck. However, the pie Turpin was hit with was hand-held, not thrown.
Document 3: The Gay Desperado: The Gay Desperado (1936) is a comedy film starring Ida Lupino, Leo Carrillo, and Nino Martini and directed by Rouben Mamoulian, produced by Mary Pickford, and originally released by United Artists. The film was restored by the UCLA Film and Television Archive and the Mary Pickford Foundation, and released on DVD in 2006 by Milestone Pictures after being out of distribution for many years.
Document 4: El Dorado (1966 film): El Dorado is a 1966 American Western film produced and directed by Howard Hawks and starring John Wayne and Robert Mitchum. Written by Leigh Brackett and loosely based on the novel "The Stars in Their Courses" by Harry Brown, the film is about a gunfighter who comes to the aid of an old friend—a drunken sheriff struggling to defend a rancher and his family against another rancher trying to steal their water. The gunfighter and drunken sheriff are helped by an aging Indian fighter and a young gambler. The supporting cast features James Caan as the young gambler, Charlene Holt, Ed Asner, Paul Fix, Arthur Hunnicutt, Michele Carey, and Christopher George.
Document 5: Universal Pictures: When Pasternak stopped producing Durbin's pictures, and she outgrew her screen persona and pursued more dramatic roles, the studio signed 13-year-old Gloria Jean for her own series of Pasternak musicals from 1939; she went on to star with Bing Crosby, W. C. Fields, and Donald O'Connor. A popular Universal film of the late 1930s was Destry Rides Again (1939), starring James Stewart as Destry and Marlene Dietrich in her comeback role after leaving Paramount Studios.
Document 6: In Gay Madrid: In Gay Madrid (1930) is an American pre-Code musical comedy, directed by Robert Z. Leonard, starring Ramón Novarro and Dorothy Jordan, and released by Metro-Goldwyn-Mayer.
Document 7: Laurel and Hardy: Prior to emerging as a team, both actors had well - established film careers. Laurel had appeared in over 50 films as an actor (while also working as a writer and director) while Hardy had been in more than 250 productions. The two comedians had previously worked together as cast members on the film The Lucky Dog in 1921. However, they were not a comedy team at that time and it was not until 1926 that they appeared in a movie short together, when both separately signed contracts with the Hal Roach film studio. Laurel and Hardy officially became a team in 1927 when they appeared together in the silent short film Putting Pants on Philip. They remained with the Roach studio until 1940 and then appeared in eight ``B ''movie comedies for 20th Century Fox and Metro - Goldwyn - Mayer from 1941 to 1945. After finishing their movie commitments at the end of 1944, they concentrated on performing in stage shows and embarked on a music hall tour of England, Ireland, and Scotland. In 1950, before retiring from the screen, they made their last film, a French - Italian co-production called Atoll K.
Document 8: Rodora: Rodora is a 1956 movie from Sampaguita Pictures about a man (Juancho Gutierrez) who falls in love with a girl (Amalia Fuentes).
Document 9: Muss 'Em Up: Muss 'Em Up is a 1936 American detective drama film directed by Charles Vidor from a screenplay by Erwin Gelsey. RKO Radio pictures premiered the film in New York City on February 1, 1936, with a nationwide opening on February 14. The film stars Preston Foster and Margaret Callahan, with a supporting cast which includes Alan Mowbray, Ralph Morgan, Big Boy Williams, and Maxie Rosenbloom.
Document 10: Exit Smiling: Exit Smiling is a 1926 comedy film directed by Sam Taylor and starring New York and London revues star Beatrice Lillie in her first (and only silent) film role and Jack Pickford, the brother of star Mary Pickford. The film was also the debut of actor Franklin Pangborn. This film is available on DVD from the Warner Archives Collection.
Document 11: Artists and Models (1937 film): Artists and Models is a 1937 black-and-white American musical comedy film, directed by Raoul Walsh, produced by Lewis E. Gensler, and starring Jack Benny and Ida Lupino.
Document 12: Jack Standing: The son of stage actor Herbert Standing and brother of Wyndham Standing (1880–1963), who also was a famous actor in the early days of film, Jack Standing first appeared in Broadway musicals such as "The Belle of New York" and "Florodora" before he went to the Biograph Company in 1909. Because he was a handsome young man, he was quickly offered many roles and signed a contract with Sigmund Lubin in 1911. Like many others from the silent film, Standing was asked to play quite everything from passionate lovers to villains or old men. In 1915, he told the "Moving Picture World" magazine, "Spare me from being a one-type actor!" He appeared in more than fifty films. An incomplete print of 1915 Mary Pickford vehicle "Fanchon the Cricket", in which Standing co-starred, has recently been found. The teenage Fred and Adele Astaire allegedly made their screen debuts in this film. Standing's greatest success was the 1916 film "Hell's Hinges", where he played the weak-willed brother of Clara Williams.
Document 13: Ruth Donnelly: Though she made her first film appearance in 1913, her Hollywood career began in earnest in 1931 and lasted until 1957. In her films she often played the wife of Guy Kibbee ("Footlight Parade", "Wonder Bar", "Mr. Smith Goes to Washington"). Among her roles was the part of Sister Michael in "The Bells of St. Mary's", starring Bing Crosby and Ingrid Bergman. Years after her final film role, she returned to the stage, understudying Patsy Kelly in the Broadway revival of "No No Nanette" with old co-star Ruby Keeler and later appearing in the touring production starring Don Ameche and Evelyn Keyes.
Document 14: Fine Manners: Fine Manners is a 1926 American black-and-white silent comedy film directed initially by Lewis Milestone and completed by Richard Rosson for Famous Players-Lasky/Paramount Pictures. After an argument with actress Gloria Swanson, director Milestone walked off the project, causing the film to be completed by Rosson, who had picked up directorial tricks while working as an assistant director to Allan Dwan. The success of the film, being Rosson's first directorial effort since he co-directed "Her Father's Keeper" in 1917 with his brother Arthur Rosson, won him a long-term contract with Famous Players-Lasky.
Document 15: Fascinating Youth: Fascinating Youth is a 1926 American silent romantic comedy film directed by Sam Wood. It starred Charles "Buddy" Rogers (in his feature debut), along with Thelma Todd and Josephine Dunn in supporting roles. Many well-known personalities made guest appearances in the film, judging a beauty contest in one scene, and Clara Bow makes a cameo appearance in her second film for Paramount Pictures.
ground_truth: Jack Pickford
sub_queries: United Artists Corporation >> founded by Answer: Mary Pickford
Mary Pickford >> sibling Answer: Jack Pickford