Question: What was the official capacity of the 1964 Summer Olympics stadium at which the Sanistand appeared?

Context articles: National Stadium (Tokyo)
Timir Pinegin
Lubomír Nácovský
Ion Tripșa
Peter Tallberg
Toda Rowing Course
Congo at the 1964 Summer Olympics
Szilárd Kun
Gil Boa
Sanistand

National Stadium (国立競技場 , Shin kokuritsu kyōgijō ) was a multi-purpose stadium in Kasumigaoka, Shinjuku, Tokyo, Japan.
 The stadium served as the main stadium for the opening and closing ceremonies, as well as being the venue for track and field events at the 1964 Summer Olympic Games.
 The Japan national football team's home matches and major football club cup finals were held at the stadium.
 The stadium's official capacity was 57,363, but the real capacity was only 48,000 seats.
Timir Alekseevich Pinegin (Russian: Тимир Алексеевич Пинегин ; 12 June 1927 – 31 January 2013) was a Russian sailor who competed for the Soviet Union in the 1956 Summer Olympics, in the 1960 Summer Olympics, in the 1964 Summer Olympics, in the 1968 Summer Olympics, and in the 1972 Summer Olympics.
Lubomír Nácovský (26 May 1935 – 10 March 1982 in Kralupy nad Vltavou) was a Czech sport shooter who competed in the 1964 Summer Olympics and in the 1968 Summer Olympics.
 He won a bronze medal in the rapid fire pistol at the 1964 Summer Olympics.
Ion Tripşa (30 March 1934 – 2001) was a Romanian sport shooter who competed in the 1964 Summer Olympics and in the 1972 Summer Olympics.
 He won a silver medal in the rapid fire pistol event at the 1964 Summer Olympics.
Peter Tallberg (15 July 1937 – 16 May 2015) was a Finnish sailor who competed in the 1960 Summer Olympics, in the 1964 Summer Olympics, in the 1968 Summer Olympics, in the 1972 Summer Olympics, and in the 1980 Summer Olympics.
The Toda Rowing Course (戸田漕艇場 , Toda Sōteijō ) is a venue that hosted the rowing event at the 1964 Summer Olympics.
 Originally completed in 1939 for the 1940 Summer Olympics that were cancelled due to World War II.
 After World War II, the venue was left in disrepair.
 When Tokyo was awarded the 1964 Summer Olympics in 1958, the venue was expanded and reconstructed.
The Republic of the Congo competed in the Olympic Games for the first time at the 1964 Summer Olympics in Tokyo, Japan.
 The Games were hosted from October 10, 1964 to October 24, 1964.
 The delegation of Congo consisted of two athletes.
 Congo did not receive medals at the 1964 Summer Olympics.
Szilárd Kun (23 March 1935 – 31 August 1987) was a Hungarian sport shooter who competed in the 1952 Summer Olympics, in the 1956 Summer Olympics, in the 1964 Summer Olympics, in the 1968 Summer Olympics and in the 1972 Summer Olympics.
 He won a silver medal at the 1952 Games.
Gilmour Stuart "Gil" Boa (8 August 1924 – 7 September 1973) was a Canadian sport shooter who competed in the 1952 Summer Olympics, in the 1956 Summer Olympics, in the 1960 Summer Olympics, in the 1964 Summer Olympics, and in the 1972 Summer Olympics.
Sanistand was a urinal for women manufactured by Japanese toilet maker giant TOTO from 1951 to 1971 and by American Standard from 1950 to 1973.
 It appeared in a bathroom in the National Stadium for female athletes during the 1964 Summer Olympics in Tokyo.
 The urinal encouraged women to urinate from a standing position, without the need to sit on a shared seat.