Question: What documentary described the making of Number of the Beast, by the artists who recorded The X Factor?

full_context: Document 1: Brave New World (Iron Maiden album): Brave New World is the twelfth studio album by English heavy metal band Iron Maiden, released on 29 May 2000. It was their first studio release since the return of longtime lead singer Bruce Dickinson (who left in 1993) and guitarist Adrian Smith (who left in 1990) in 1999, as well as the band's first studio recording as a six-piece, as Janick Gers, who replaced Smith in 1990, remained with the band.
Document 2: Run to the Hills: "Run to the Hills" is a song by the English heavy metal band Iron Maiden. It was released as their sixth single and the first from the band's third studio album, "The Number of the Beast" (1982). Credited solely to the band's bassist, Steve Harris, although significant contributions were made by lead vocalist Bruce Dickinson, it remains one of their most popular songs, with VH1 ranking it No. 27 on their list of the 40 Greatest Metal Songs and No. 14 on their list of the Greatest Hard Rock Songs.
Document 3: Visions of the Beast: Visions of the Beast was released by Iron Maiden on 2 June 2003 and contains every promotional video through 2001's "Rock in Rio". It is basically an updated version of "" and "From There to Eternity". It also includes never-before-seen Camp Chaos animated versions of six definitive Iron Maiden songs, interactive menus and discographies, and some special hidden extras.
Document 4: The Number of the Beast (song): "The Number of the Beast" is a song by the English heavy metal band Iron Maiden. It is Iron Maiden's seventh single release, and the second single from their 1982 studio album of the same name. It was reissued in 2005 and also prior to that in 1990 in "The First Ten Years" box set on CD and 12" vinyl, in which it was combined with the previous single, "Run to the Hills".
Document 5: Tenth Dimension: Tenth Dimension is the second studio album by English heavy metal band Blaze Bayley, then known as Blaze, released in 2002. It is a concept album.
Document 6: Iron Maiden: Iron Maiden are an English heavy metal band formed in Leyton, East London, in 1975 by bassist and primary songwriter Steve Harris. The band's discography has grown to thirty-nine albums, including sixteen studio albums, twelve live albums, four EPs, and seven compilations.
Document 7: The X Factor (album): The X Factor is the tenth studio album by English heavy metal band Iron Maiden, released on 2 October 1995 through EMI. It is the first of two albums by the band to include Blaze Bayley, formerly of Wolfsbane, as vocalist, replacing Bruce Dickinson who left the band following their previous tour to pursue a solo career. The album takes a darker tone than the band's first nine releases, due to the lyrics being based on personal issues surrounding Steve Harris at the time, who was in the midst of a divorce. This is reflected in the cover artwork, which graphically depicts the band's mascot, Eddie, being vivisected by machine.
Document 8: Run to the Hills: ``Run to the Hills ''is a song by the English heavy metal band Iron Maiden. It was released as their sixth single and the first from the band's third studio album, The Number of the Beast (1982). Credited solely to the band's bassist, Steve Harris, although significant contributions were made by lead vocalist Bruce Dickinson, it remains one of their most popular songs, with VH1 ranking it No. 27 on their list of the 40 Greatest Metal Songs and No. 14 on their list of the Greatest Hard Rock Songs.
Document 9: Beast over Hammersmith: Beast over Hammersmith is a live album by the British heavy metal band Iron Maiden, released on 4 November 2002. Recorded 20 years previously, during The Beast On The Road tour at the Hammersmith Odeon, the footage was specially co-produced and mixed by Steve Harris and Doug Hall to be a part of the Eddie's Archive box set. Even though this album contains material from "The Number of the Beast", it was actually recorded two days prior to its release (although "Run to the Hills" had already been released as a single).
Document 10: Rock in Rio (album): The video release, which was issued on DVD, VHS and UMD, was edited by bassist and founder member Steve Harris. In addition to the concert, the second disc also includes three special features with interviews with band members, a short documentary on the day in the life of Iron Maiden, and photos by official photographer, Ross Halfin.
Document 11: British Lion (album): British Lion is the debut solo album from Steve Harris, best known as the bassist and primary songwriter for the British heavy metal band Iron Maiden. The album was announced on 18 July 2012 and released on 24 September.
Document 12: Classic Albums: Iron Maiden – The Number of the Beast: Classic Albums: Iron Maiden -- The Number of the Beast is a documentary about the making of the album of the same name by the British heavy metal band Iron Maiden, released on 26 November 2001 as part of the Classic Albums documentary series. Directed by Tim Kirkby, it featured cuts from the title track, ``Children of the Damned '',`` Run to the Hills'', and ``The Prisoner, ''in addition to extended interviews and live footage of`` Hallowed Be Thy Name'', recorded during the band's performance at the Rock in Rio festival in 2001.
Document 13: The Number of the Beast (song): ``The Number of the Beast ''is a song by the English heavy metal band Iron Maiden. It is Iron Maiden's seventh single release, and the second single from their 1982 studio album of the same name. It was reissued in 2005 and also prior to that in 1990 in The First Ten Years box set on CD and 12'' vinyl, in which it was combined the previous single,`` Run to the Hills ''.
Document 14: Fear of the Dark (Iron Maiden album): Fear of the Dark is the ninth studio album released by English heavy metal band Iron Maiden. Released on 11 May 1992, it was their third studio release to top the UK albums chart and the last to feature Bruce Dickinson as the group's lead vocalist until his return in 1999.
Document 15: Ed Hunter: Ed Hunter is a greatest hits album and video game released in 1999 by British heavy metal band Iron Maiden and Synthetic Dimensions respectively. The game objective consists of following Iron Maiden's mascot, Eddie, through various levels depicting the band's past album covers. The accompanying CDs have the group's most popular songs, as selected by fans on the band's official website.
ground_truth: Classic Albums: Iron Maiden -- The Number of the Beast
sub_queries: The X Factor >> performer Answer: Iron Maiden
Iron Maiden making of number of the beast Answer: Classic Albums: Iron Maiden -- The Number of the Beast