user: Question: What's the highest week for the day of October 21, 1956?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 30, 1956', 'at San Francisco 49ers', 'W 38–21', 41751.0]
SQL:

assistant: SELECT MAX("Week") FROM "Table" WHERE "Date" = 'October 21, 1956';