user: Question: How many weeks have an Opponent of at san francisco 49ers, and an Attendance smaller than 34354?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 21, 1975', 'at Philadelphia Eagles', 'W 23–14', 60798.0]
SQL:

assistant: SELECT COUNT("Week") FROM "Table" WHERE "Opponent" = 'at san francisco 49ers' AND "Attendance" < 34354.0;