Question: How many teams play in this league in which Antonio Carlos Dos Santos's club Schaffhausen competes?

Context paragraphs:
Marc Dos Santos: Marc Dos Santos (born May 26, 1977) is a Canadian soccer manager with experience in the United Soccer League, North American Soccer League, and Major League Soccer.  He currently is the manager of the San Francisco Deltas of the North American Soccer League, beginning play in the 2017 season.  Most recently, he was the manager of the Swope Park Rangers of the United Soccer League, an affiliate of Sporting Kansas City of Major League Soccer.  The North American Soccer League Coach of the Year in 2015, Dos Santos led the Ottawa Fury FC to the NASL Championship Final after a first-place finish in the Fall Season.  Previously, he focused on youth initiatives in Brazil with FC Primeira Camisa (U-20's) and SE Palmeiras (U-15's), culminating with a Copa do Brasil Sub-15 championship and a technical director position with Desportivo Brasil.  The Montreal native was first hired by the Montreal Impact in January 2007 to lead the club's reserve team, Trois-Rivieres Attak FC, in the Canadian Soccer League.  After leading the squad to titles in their initial two seasons – first as 2007 Open Canada Cup champions, then as 2008 CSL National Division champions – Dos Santos was added to the Impact's technical staff as an assistant coach in June 2008 and became head coach in May 2009.  During his tenure, the Impact won the inaugural Canadian Championship in 2008 to claim the Voyageurs Cup and a berth in the 2008-09 CONCACAF Champions League.  Dos Santos then led Montreal through three different leagues in consecutive campaigns, winning the USL First Division title in 2009 before transitioning into USSF Division 2 in 2010 and the North American Soccer League in 2011.

The Music According to Antonio Carlos Jobim: The Music According to Antonio Carlos Jobim (Portuguese: A Música Segundo Tom Jobim ) is a 2012 Brazilian documentary film, directed by Nelson Pereira dos Santos and Dora Jobim that tells the history of the singer and songwriter Tom Jobim.

Antônio Carlos (footballer): Antônio Carlos dos Santos Aguiar (born 22 June 1983), or simply Antônio Carlos, is a Brazilian footballer who plays for Avaí as a central defender.

Swiss Challenge League: The Swiss Challenge League or Brack.ch Challenge League is a professional league and the second highest tier of the Swiss football league system.  Ten teams play in the Challenge League.  The winners of the league are promoted to the Super League, the bottom team is relegated to the 1.  Liga Promotion.

António Carlos dos Santos: Antonio Carlos Dos Santos (born October 3, 1979) is a Brazilian footballer who plays as a midfielder for Swiss Challenge League club Schaffhausen.  He is feared for his dangerous free kicks.

Neider dos Santos: Neider dos Santos is a Brazilian football coach who is currently the manager of Jamaican club side Montego Bay United.  He has previously managed Simba SC in Tanzania, as well as the youth teams of Brazilian clubs Vasco da Gama and Botafogo, plus the national teams of Cayman Islands and Guyana.  Dos Santos took over as manager of Jamaican club Village United in late 2010, having spent the previous four years as manager of the Bahamas national team.  After leaving Jamaican club Village United in early 2011, Dos Santos was hired by newly promoted Montego Bay United in October 2011.

João Carlos dos Santos: João Carlos dos Santos or simply known as João Carlos (born 10 September 1972 in Sete Lagoas, Brazil) is a Brazilian former footballer who played as a defender.  He played for the Brazilian national team at 1999 Copa América in Paraguay.

Carlos Ponck: Carlos dos Santos Rodrigues (born 13 January 1995), known as Carlos Ponck or simply Ponck, is a Cape Verdean professional footballer who plays as a midfielder for Portuguese club C.D. Aves on loan from Benfica.

Portuguese Basketball League Cup: The Portuguese Basketball League Cup (Taça da Liga) is a competition for Portuguese teams that play in LPB.  It was played by the clubs of the former LCB, which was a professional league.  After the LCB folded in 2008, the League Cup ended as well.  In the 2009–10 season, the competition was restarted as Hugo dos Santos Cup (Taça Hugo dos Santos), in honor of the former president of the Portuguese Basketball Federation.

Anibal dos Santos: Aníbal António "Anibalzinho" dos Santos Júnior (Aníbal dos Santos, born 1971 or 1972) is a Portuguese criminal convicted of masterminding the November 22, 2000, murder of Carlos Cardoso, a journalist investigating bank fraud in Mozambique's Central Bank (BCM).  After a first trial "in absentia" in 2003, one failed and two successful escapes and two extraditions (from South Africa and Canada), dos Santos was sentenced to 30 years imprisonment in January 2006.  Dos Santos maintained his innocence throughout the trial.  As of April, 2008, dos Santos remained in Mozambican custody and was investigated in another murder case, that of BCM lawyer Albano Silva.

Supporting paragraphs: António Carlos dos Santos Swiss Challenge League
Answer: Ten