user: Question: What is the highest week for the san diego chargers with an attendance that is less than 53455?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 17, 1972', 'at Pittsburgh Steelers', 'L 34–28', 50141.0]
SQL:

assistant: SELECT MAX("Week") FROM "Table" WHERE "Opponent" = 'san diego chargers' AND "Attendance" < 53455.0;