Question: Who is from the United States, Radek Štěpánek or Brian Gottfried?

Context paragraphs:
2007 Countrywide Classic: The 2007 Countrywide Classic was a men's tennis tournament played on outdoor hard courts at the Los Angeles Tennis Center in Los Angeles, California in the United States and was part of the International Series of the 2007 ATP Tour and of the 2007 US Open Series.  It was the 81st edition of the Los Angeles Open and the tournament ran from July 16, 2006 through July 23, 2006.  Unseeded Radek Štěpánek won his first title of the year, and second career title.

Radek Štěpánek: Radek Štěpánek (] ; born 27 November 1978) is a professional tennis player from the Czech Republic.  His career-high singles ranking is world No. 8 and best doubles ranking is world No. 4.  Štěpánek's biggest achievements are reaching two Masters 1000 event finals and the quarterfinals of Wimbledon in 2006, as well as winning the deciding match for Czech Republic's Davis Cup winning team in 2012 and again in 2013.  In doubles, he won his first Grand Slam title at the 2012 Australian Open, along with Indian partner Leander Paes, defeating the Bryan Brothers in the final.  Paes and Štěpánek also won the men's doubles title at the 2013 US Open, defeating Bruno Soares and Alexander Peya in the final.

Mario H. Gottfried Gutiérrez: Mario Héctor Gottfried Gutiérrez (September 7, 1919, – November 2, 1999,) was a renowned businessman in the Mexican electric industry, and captain of the Air Force of the United States.  Founder of a group of Mexican companies, such as Reliance de Mexico, S.A. de C.V., and Potencia Industrial, S.A.

Gottfried Blocklinger: Gottfried Blocklinger was a Rear-admiral in the United States Navy;

Audition Day: "Audition Day" is the fourth episode of the fourth season of the American television comedy series "30 Rock", and the 62nd overall episode of the series.  The episode was written by supervising producer Matt Hubbard and directed by Beth McCarthy-Miller.  It originally aired on the National Broadcasting Company (NBC) network in the United States on November 5, 2009.  Guest stars in this episode include Craig Castaldo, Nick Fondulis, Daniel Genalo, Marceline Hugot, Angela Grovey, Michael Mulheren, David Perlman, and Brian Williams.  There are cameos by Gilbert Gottfried, Martin Scorsese, and Christopher Walken, though, the three did not appear as themselves, but provided their voices in the episode.

John G. Cullmann: John Gottfried Cullmann (July 2, 1823 – December 3, 1895) was a German businessman and political activist who emigrated to the United States as a result of his financial ruin related to participation in the Revolution of 1848.  Born in Frankweiler in the Rheinpfalz in what was then the Kingdom of Bavaria, Cullmann was the son of a school principal.  At the age of 13, he began attending the Zweibrücken Polytechnic Institute, taking a degree in engineering.  He married the daughter of a wealthy banking family, Josephine Low, and settled in the town of Neustadt, founding an export business there.

1976 Pacific Southwest Open: The 1976 Pacific Southwest Open, also known under its sponsorship name 1976 Arco–Pacific Southwest Open, was a men's tennis tournament played on indoor hard courts at the Pauley Pavilion in Los Angeles, California in the United States.  The event was part of the Grand Prix tennis circuit and categorized as four-star.  It was the 50th edition of the tournament and ran from September 20 through September 27, 1976.  Tenth-seeded Brian Gottfried won the singles title and $20,000 first-prize money.

Brian Gottfried: Brian Edward Gottfried (born January 27, 1952) is a retired tennis player from the United States who won 25 singles titles and 54 doubles titles during his professional career.  The right-hander was the runner-up at the 1977 French Open and achieved a career-high singles ranking on the ATP tour on June 19, 1977, when he became World No. 3.

Ernesto Schmitt: Ernesto Gottfried Schmitt (born August 1971 in the United States) is a German technology entrepreneur based in the United Kingdom.

Nick Bollettieri: Born in Pelham, New York, to immigrant Italian parents, Nick Bollettieri attended Pelham Memorial High School.  He was a charter member of the Beta Lambda Chapter of the Omega Gamma Delta Fraternity and he graduated in 1949.  In 1953, he graduated from Spring Hill College (Mobile, Alabama) with a degree in philosophy.  After serving with the United States Army, attaining the rank of First Lieutenant, in 1956 he turned to teaching tennis after dropping out of the University of Miami Law School.  Bollettieri's first students included Brian Gottfried.  His first formal tennis camp was at Wayland Academy in Beaver Dam, Wisconsin.

Supporting paragraphs: Radek Štěpánek Brian Gottfried
Answer: Brian Edward Gottfried