Question: What is the population of the largest city in Iraq, who's 1956–57 Iraq FA Cup Championship was open to teams from the capital?

full_context: Document 1: Baghdad: Baghdad (Arabic: بغداد‎ ‎ , ) is the capital of Iraq. The population of Baghdad, as of 2016 , is approximately 8,765,000, making it the largest city in Iraq, the second largest city in the Arab world (after Cairo, Egypt), and the second largest city in Western Asia (after Tehran, Iran).
Document 2: 1988–89 Iraq FA Cup: The 1988–89 Iraq FA Cup was the 12th edition of the Iraq FA Cup. The tournament was won by Al-Zawraa for the fifth time, beating Al-Tayaran 3–0 in the final. The first two rounds were between teams from the lower division, before the top-flight clubs entered at the round of 32.
Document 3: Riyadh: Riyadh (/rɨˈjɑːd/; Arabic: الرياض‎ ‎ "ar-Riyāḍ" ] ) is the capital and most populous city of Saudi Arabia. It is also the capital of Riyadh Province and belongs to the historical regions of Najd and Al-Yamama. It is situated in the center of the Arabian Peninsula on a large plateau and home to more than six million people.
Document 4: Baku: Baku ( , ; Azerbaijani: "Bakı" , ] ) is the capital and largest city of Azerbaijan, as well as the largest city on the Caspian Sea and of the Caucasus region. Baku is located 28 m below sea level, which makes it the lowest lying national capital in the world and also the largest city in the world located below sea level. It is located on the southern shore of the Absheron Peninsula, alongside the Bay of Baku. At the beginning of 2009, Baku's urban population was estimated at just over two million people. Officially, about 25 percent of all inhabitants of the country live in Baku's metropolitan area.
Document 5: Damascus: Damascus (Arabic: دمشق‎ ‎ "Dimashq " ] , ] ) is the capital and likely the largest city of Syria, following the decline in population of Aleppo due to the battle for the city. It is commonly known in Syria as "ash-Sham" (Arabic: الشام‎ ‎ "ash-Shām ") and nicknamed as the "City of Jasmine" (Arabic: مدينة الياسمين‎ ‎ "Madīnat al-Yāsmīn "). In addition to being one of the oldest continuously inhabited cities in the world, Damascus is a major cultural centre of the Levant and the Arab world. The city has an estimated population of 1,711,000 as of 2009 .
Document 6: 1984–85 Iraq FA Cup: The 1984–85 Iraq FA Cup was the ninth edition of the Iraq FA Cup. The tournament was abandoned at the semi-final stage with Al-Rasheed, Al-Tayaran, Al-Talaba and Al-Tijara being the four teams still remaining in the competition. It was abandoned along with the 1984–85 Iraqi National League due to the national team's World Cup qualifying campaign, and no champions were announced for either tournament.
Document 7: 2016–17 Iraq FA Cup: The 2016–17 Iraq FA Cup was the 28th edition of the Iraqi knockout football cup competition, the main domestic cup in Iraqi football. A total of 19 teams from the Iraqi Premier League and 41 teams from the Iraq Division One participated. It started on 2 December 2016 and the final was played at the Al-Sinaa Stadium in Baghdad on 22 August 2017 (the usual venue, Al-Shaab Stadium, was closed for renovation). It was the second Iraq FA Cup final to be held outside of Al-Shaab Stadium, with the first being in 2003.
Document 8: 1987–88 Iraq FA Cup: The 1987–88 Iraq FA Cup was the 11th edition of the Iraq FA Cup. The tournament was won by Al-Rasheed for the second consecutive time, beating Al-Zawraa 4–3 on penalties in the final after a 0–0 draw. Al-Rasheed won the 1987–88 Iraqi National League as well to complete their second double in a row. It was also Al-Zawraa's first FA Cup final defeat.
Document 9: Baghdad Tower: Baghdad Tower (Arabic: برج بغداد‎ ‎ ) (previously called International Saddam Tower) is a 205 m TV tower in Baghdad, Iraq. The tower opened in 1994 and replaced a communications tower destroyed in the Gulf War. A revolving restaurant and observation deck are located on the top floor. After the 2003 invasion of Iraq, the tower was occupied by American soldiers and was renamed.
Document 10: Al-Baggara: Al-Baggara (Arabic: السادة البَقارة‎ ‎ , also spelled "Baqqara", "Buggara") is a large deep-rooted Sunni Muslim Arab tribe widespread through Iraq, Syria and slightly of them in Turkey and Jordan, And they were called by this name in relation to their ancient grandfather Muhammad Baqir. There is a tribe with the same name in western Sudan's Darfur area and neighbouring Chad.They are also known as Baggara Arabs in English.They are cattle herders.
Document 11: 2015–16 Iraqi Premier League: The 2015–16 Iraqi Premier League (known officially as the "Fuchs Iraqi Premier League" for sponsorship reasons) was the 42nd season of the Iraqi Premier League since its establishment in 1974. The season started on 15 September 2015 and concluded on 22 May 2016. Al-Zawraa won a record 13th Iraqi Premier League title, finishing one point ahead of defending champions Naft Al-Wasat. Al-Zawraa went through all 24 matches without a single defeat: the eighth time that a team has won the league undefeated since the league's inception in 1974.
Document 12: 1956–57 Iraq FA Cup Championship: The 1956–57 Iraq FA Cup Championship was the 2nd season of what is now known as the League of the Institutes (the top division of Iraqi football from 1948 to 1974), and it was the first national championship to be held since the 1948–49 season. Unlike that season, this time it was open to teams from Baghdad only.
Document 13: Al-Quwa Al-Jawiya: Nadi Al-Quwa Al-Jawiya Al-Riyadhi ("Air Force Athletic Club", Arabic: نادي القوة الجوية الرياضي‎ ‎ ) is an Iraqi football club based in Rusafa District, Baghdad that competes in the Iraqi Premier League, the top-flight of Iraqi football. Founded in 1931, it is the oldest existing football club in Iraq. It is also one of Iraq's most successful clubs, having won eleven league titles, the most recent being in the 2016–17 season. The club has won four Iraq FA Cups as well as a joint-record three Iraqi Elite Cups and two Iraqi Super Cups. It is also the first of only two clubs to win all four of the aforementioned trophies (League, FA Cup, Elite Cup, Super Cup) in the same season (the 1996–97 season).
Document 14: Abu Ghraib: Abu Ghraib ( ; Arabic: أبو غريب‎ ‎ , "Abū Ghurayb") is a city in the Baghdad Governorate of Iraq, located just west of Baghdad's city center, or northwest of Baghdad International Airport. It has a population of 189,000 (2003). The old road to Jordan passes through Abu Ghraib. The government of Iraq created the city and Abu Ghraib District in 1944.
Document 15: Iraqi Super Cup: The Iraqi Super Cup (Arabic: كأس السوبر العراقي), previously called Al-Muthabara Cup (Arabic: كأس المثابرة, meaning "Perseverance Cup"), is Iraqi football's annual match contested between the champions of the previous Iraqi Premier League season and the holders of the Iraq FA Cup at Al-Shaab Stadium. If the Premier League champions also won the FA Cup then the league runners-up provide the opposition. Generally ranked below the Iraq FA Cup and the now-defunct Iraqi Elite Cup in terms of importance, the fixture is a recognised football super cup.
ground_truth: 8,765,000