Question: Which judge of Strictly Come Dancing is a professional ballroom dancer?

full_context: Document 1: Strictly Come Dancing (series 13): Strictly Come Dancing returned for its thirteenth series on BBC One with a launch show on 5 September 2015, with the live shows starting on 25 September 2015. Tess Daly and Claudia Winkleman returned to present the launch show and the live shows while Zoë Ball returned to present "" on BBC Two. Len Goodman, Bruno Tonioli and Craig Revel Horwood returned as judges for their thirteenth series, along with Darcey Bussell who returned for her fourth series as a judge.
Document 2: Strictly Come Dancing (series 9): Strictly Come Dancing returned for its ninth series on 10 September 2011 with a launch show, with the live shows starting on 30 September and 1 October 2011. The show was broadcast from Wembley Arena on 19 November with all proceeds going to the BBC charity, Children in Need. The final took place at the Blackpool Tower Ballroom and was the first episode in 3D, and was shown on BBC HD and 18 cinemas around the country. As in series 8 there are 14 couples with one new male professional, Pasha Kovalev, replacing Jared Murillo.
Document 3: Strictly Come Dancing (series 14): Strictly Come Dancing returned for its fourteenth series with a launch show on 3 September on BBC One, with the live shows starting on 23 September 2016. Tess Daly and Claudia Winkleman returned as hosts, while Zoë Ball returned to host "" on BBC Two. Len Goodman, Bruno Tonioli, Craig Revel Horwood and Darcey Bussell returned as judges. This was Goodman's final series as a judge.
Document 4: Bruno Tonioli: Bruno Tonioli (] ; born 25 November 1955) is an Italian choreographer, dancer, and TV personality.
Document 5: Strictly Come Dancing (series 12): Strictly Come Dancing returned for its twelfth series beginning from 7 September 2014 with a launch show, with the live shows starting on 26 and 27 September. Tess Daly returned to present the main show on BBC One alongside Claudia Winkleman, who has been promoted to co-presenter in addition to the results show after Bruce Forsyth decided to leave the show after the eleventh series; however, Forsyth will continue to host the Christmas and Children in Need specials. Zoë Ball returned as presenter of spin-off show "" on BBC Two. Judges Len Goodman, Bruno Tonioli, Craig Revel Horwood and Darcey Bussell also returned.
Document 6: Strictly Come Dancing (series 8): Strictly Come Dancing returned for its eighth series on BBC One with a red carpet launch show on 11 September 2010, and the competitive live shows began on 1 October. The series concluded on 18 December when Kara Tointon and Artem Chigvintsev won the competition. According to BARB data, this series was the consistently highest rated of the show to date, peaking at 14.28 million viewers. Len Goodman, Bruno Tonioli, Craig Revel Horwood and Alesha Dixon returned as judges.
Document 7: Jonathan Wilkins: Jonathan Wilkins is an English ballroom dancer and dance teacher, born in London. He holds many titles in Professional Ballroom Dancing including being 10 times Professional Ballroom Champion, 1997 - 2007 ( in a partnership with Katusha Demidova which lasted eleven years, and brought considerable success). In 2004 they won the World Classic Showdance Championship, which is one of the subsidiary World Dance Council Dance Sport events. Their final result was to win the WDC Open Professional Ballroom title at the USA Open in Orlando, Florida 2007.
Document 8: Strictly Come Dancing (series 7): Strictly Come Dancing returned for its seventh series on 18 September 2009 on BBC One. Bruce Forsyth and Tess Daly returned as presenters of the main show on BBC One, whilst Claudia Winkleman presented spin-off show "" on BBC Two. Len Goodman, Bruno Tonioli and Craig Revel Horwood returned as judges. Series 5 winner Alesha Dixon joined the judging panel as a replacement for Arlene Phillips. Darcey Bussell was a guest judge from the quarter final onwards.
Document 9: Darcey Bussell: Darcey Andrea Bussell CBE (born Marnie Mercedes Darcey Pemberton Crittle 27 April 1969) is a retired English ballerina, and is currently one of the four judges on the BBC reality show "Strictly Come Dancing".
Document 10: Len Goodman: Leonard Gordon Goodman (born 25 April 1944) is an English professional ballroom dancer, dance judge, and coach.
Document 11: Strictly Come Dancing (series 10): Strictly Come Dancing returned for its tenth series and began with the launch show on 15 September 2012. The live shows commenced on 5 October. Fourteen celebrities took part - the same number as the previous year. Bruce Forsyth and Tess Daly returned to present the main show on BBC One and Claudia Winkleman returned to present the results show with Daly. Zoë Ball returned to present spin-off show "". Judges Len Goodman, Bruno Tonioli and Craig Revel Horwood all returned and were joined on the judging panel by series 7 guest judge Darcey Bussell, who replaced Alesha Dixon.
Document 12: Brendan Cole: Brendan Cole (born 23 April 1976) is a New Zealand ballroom dancer, specialising in Latin American dancing. He is most famous for appearing as a professional dancer on the BBC One show, "Strictly Come Dancing". From 2005 to 2009, he was a judge on the New Zealand version of the show, "Dancing with the Stars".
Document 13: Michael Malitowski: Michael Malitowski is a ballroom dancer, a former World Latin Dance Champion with his partner Joanna Leunis. Michael (christened "Michał") was born 28 May 1980, in Zielona Góra, Poland. His partnership with Leunis has, since 2002, resulted in a string of victories: in 2008 and 2009 they won the World Professional Latin title, and in 2012 they won first place in Latin dance at the Blackpool Dance Festival. This is the prestigious Open British Championships held every year in Blackpool, England. Before that, he won the Polish Latin dance championship four times with Iwona Golczak.
Document 14: Strictly Come Dancing (series 5): Strictly Come Dancing returned for its fifth series on 29 September 2007 on BBC One. Bruce Forsyth and Tess Daly returned as co-presenters of the main show on BBC One, while Claudia Winkleman returned to present spin-off show "" on BBC Two. Len Goodman, Bruno Tonioli, Craig Revel Horwood and Arlene Phillips returned to the judging panel for their fifth series.
Document 15: Strictly Come Dancing (series 11): Strictly Come Dancing returned for its eleventh series beginning with a launch show on 7 September 2013, with the live shows starting on 27 and 28 September 2013. Bruce Forsyth and Tess Daly continued to co-present the main show on BBC One, with Claudia Winkleman returning to present the results show alongside Daly. Zoë Ball returned as presenter of "" on BBC Two. Len Goodman, Bruno Tonioli, Craig Revel Horwood and Darcey Bussell also returned as judges.
ground_truth: Len Goodman