Question: How many tours in the Iraq War did the author of the autobiography American Sniper do ?

full_context: Document 1: Edward Byers: Edward C. Byers, Jr. (born August 4, 1979) is a United States Navy SEAL who received the Medal of Honor on February 29, 2016 for the rescue of a civilian in Afghanistan in 2012. He is the most decorated living U.S. Navy SEAL. Along with United States Army Major William D. Swenson, he is one of two Medal of Honor recipients serving on active duty.
Document 2: Billy Lynn's Long Halftime Walk: Billy Lynn's Long Halftime Walk is a satirical war novel written by Ben Fountain, which was published in early May 2012 by Ecco Press, a publishing imprint of HarperCollins. The novel chronicles the experience of a group of Iraq War veterans who are hailed as heroes and sent on a victory tour following their engagement in an intense firefight that happened to be caught on camera. Set during a single day, the story primarily focuses on Specialist Billy Lynn's perspective as he struggles to reconnect with his family and come to grips with the huge disconnect between the realities of the war at home and the war overseas as Bravo Squad is sent to participate in the Dallas Cowboys' Thanksgiving halftime show. The novel's primary themes include fraternity, the commercialization of war, and what it really means to support the war when the real costs are barely felt by the majority of US citizens at home.
Document 3: Ron Kovic: Ronald Lawrence "Ron" Kovic (born July 4, 1946) is an American anti-war activist, writer, and former United States Marine Corps sergeant, who was wounded and paralyzed in the Vietnam War. He is best known as the author of his 1976 memoir "Born on the Fourth of July", which was made into the Academy Award–winning eponymous film in 1989 directed by Oliver Stone.
Document 4: Brandon Webb (author): Brandon Tyler Webb (born 1974) is a former United States Navy SEAL and SEAL Sniper Head Instructor, with one combat deployment to Afghanistan and one to Iraq. He served as the Navy SEAL Sniper Course Manager, where he developed new curricula and trained snipers, including Chris Kyle. He is the editor in chief of SOFREP and a media commentator on snipers and related Special Operations Forces military issues. Webb is the co-author of "The 21st Century Sniper: A Complete Practical Guide". He is the author of "The Red Circle", his memoir, and "The Making of a Navy Seal".
Document 5: Kevin Lacz: Kevin “Dauber” Lacz is a United States Navy SEAL veteran who served two tours in the Iraq War with SEAL Team 3. His platoon's 2006 deployment to Ramadi has been discussed in several books, including Dick Couch’s "The Sheriff of Ramadi", Jim DeFelice’s "Code Name: Johnny Walker", and Chris Kyle's New York Times best-selling autobiography, "American Sniper". Lacz’s presence in the book led to his involvement in the production of and eventual casting in the Clint Eastwood-directed Oscar-winning biopic of the same name (starring Bradley Cooper).
Document 6: Dale Dye: Captain Dale Adam Dye Jr., USMC (Ret.) (born October 8, 1944) is an American actor, technical advisor, radio personality and writer. A decorated Marine veteran of the Vietnam War, Dye is the founder and head of Warriors, Inc., a technical advisory company specializing in portraying realistic military action in Hollywood films. Dye has also offered his expertise to television, such as the HBO miniseries "Band of Brothers" and "The Pacific", and video games, including the "Medal of Honor" series.
Document 7: Chris Kyle: Christopher Scott "Chris" Kyle (April 8, 1974 – February 2, 2013) was a United States Navy SEAL veteran and sniper. Kyle served four tours in the Iraq War and was awarded several commendations for acts of heroism and meritorious service in combat. He was awarded one Silver Star Medal, four Bronze Star Medals with "V" devices, a Navy and Marine Corps Achievement Medal and numerous other unit and personal awards.
Document 8: American Sniper (book): American Sniper: The Autobiography of the Most Lethal Sniper in U.S. Military History is an autobiography by United States Navy SEAL Chris Kyle, written with Scott McEwen and Jim DeFelice. With 255 kills, 160 of them officially confirmed by the Pentagon, Kyle is the deadliest marksman in U.S. military history. The book was published by William Morrow and Company on January 2, 2012 and appeared on "The New York Times" Best Seller list for 37 weeks.
Document 9: Howard E. Wasdin: Dr. Howard E. Wasdin (born Howard E. Wilbanks on November 8, 1961) is a former member of the United States Navy who served as a sailor in the Atlantic Fleet as well as a Navy SEAL. Following his honorable discharge, he co-wrote the autobiographical memoir "SEAL Team Six: Memoirs of an Elite Navy SEAL Sniper". He also wrote "I Am a SEAL Team Six Warrior: Memoirs of an American Soldier". Wasdin served in operation Desert Storm and was part of the operation to capture Mohamed Farrah Aidid, a Somalian warlord. It was in the operation that Wasdin was shot and almost lost his leg. After 12 years of service, he now lives in Georgia where he operates a chiropractic clinic.
Document 10: Jocko Willink: John "Jocko" Willink (September 8, 1971) is an American podcaster, author, martial artist and retired United States Navy SEAL. He received the Silver Star and Bronze Star for his service in the Iraq War. Willink was commander of SEAL Team Three's Task Unit Bruiser during the Battle of Ramadi. Other notable members of Task Unit Bruiser included Leif Babin, Ryan Job, JP Dinnell, Marc Alan Lee, Michael Monsoor, Kevin Lacz and Chris Kyle.
Document 11: Lone Survivor: Lone Survivor is a 2013 American biographical war thriller film based on the 2007 non-fiction book of the same name by Marcus Luttrell with Patrick Robinson. Set during the war in Afghanistan, the film dramatizes the unsuccessful United States Navy SEALs counter-insurgent mission Operation Red Wings, during which a four-man SEAL reconnaissance and surveillance team was tasked to track down and kill Taliban leader Ahmad Shah. Written and directed by Peter Berg, it stars Mark Wahlberg, Taylor Kitsch, Emile Hirsch, Ben Foster, and Eric Bana.
Document 12: Marcus Luttrell: Marcus Luttrell, (born November 7, 1975) is a former United States Navy SEAL who received the Navy Cross and Purple Heart for his actions in June 2005 against Taliban fighters during Operation Red Wings. Luttrell was a Hospital Corpsman First Class by the end of his eight-year career in the United States Navy.
Document 13: American Sniper: American Sniper is a 2014 American biographical war drama film directed by Clint Eastwood and written by Jason Hall. It is loosely based on the memoir "American Sniper: The Autobiography of the Most Lethal Sniper in U.S. Military History" (2012) by Chris Kyle, with Scott McEwen and Jim DeFelice. The film follows the life of Kyle, who became the deadliest marksman in U.S. military history with 255 kills from four tours in the Iraq War, 160 of which were officially confirmed by the Department of Defense. While Kyle was celebrated for his military successes, his tours of duty took a heavy toll on his personal and family life. The film was produced by Eastwood, Robert Lorenz, Andrew Lazar, Bradley Cooper, and Peter Morgan. It stars Cooper as Kyle and Sienna Miller as his wife Taya, with Luke Grimes, Jake McDorman, Cory Hardrict, Kevin Lacz, Navid Negahban, and Keir O'Donnell in supporting roles.
Document 14: The Hurt Locker: The Hurt Locker is a 2008 American war thriller film about an Iraq War Explosive Ordnance Disposal team who are being targeted by insurgents with booby traps, remote control detonations and ambushes. Directed by Kathryn Bigelow, it stars Jeremy Renner, Anthony Mackie, Brian Geraghty, Christian Camargo, Ralph Fiennes, David Morse, and Guy Pearce. The film shows soldiers' varying psychological reactions to the stress of combat, which though intolerable to some, is addictive to others. The story unfolds after a staff sergeant is killed by an insurgent trap and an apparently calm veteran is brought in to head the squad. His comrades suspect that their new team leader is being driven to take terrifying risks. Writer Mark Boal drew on his experience during embedded access to provide an authentic background for the production, although certain army procedures were portrayed with artistic licence.
Document 15: Michael P. Murphy: Michael Patrick "Murph" Murphy (May 7, 1976 – June 28, 2005) was a United States Navy SEAL officer who was awarded the U.S. military's highest decoration, the Medal of Honor, for his actions during the War in Afghanistan. He was the first member of the U.S. Navy to receive the award since the Vietnam War. His other posthumous awards include the Silver Star Medal (which was later upgraded to the Medal of Honor) and the Purple Heart.
ground_truth: four