user: Question: How many locations have been used for ballparks named Memorial Stadium?
Columns: ['Ballpark', 'Location', 'Team', 'Opened', 'Closed', 'Demod', 'Current Status']
Types: ['text', 'text', 'text', 'real', 'real', 'real', 'text']
Sample row: ['Arlington Stadium', 'Arlington, Texas', 'Rangers', 1965.0, 1993.0, 1994.0, 'Now parking for Rangers Ballpark in Arlington .']
SQL:

assistant: SELECT COUNT("Location") FROM "Table" WHERE "Ballpark" = 'Memorial Stadium';