Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Week | Date | Opponent | Result | Attendance |
| --- | --- | --- | --- | --- |
| 1.0 | September 5, 1981 | at Tampa Bay Buccaneers | L 21-13 | 66287.0 |
| 2.0 | September 14, 1981 | Oakland Raiders | L 36-10 | 47186.0 |
| 3.0 | September 20, 1981 | Detroit Lions | W 26-24 | 45350.0 |
| 4.0 | September 27, 1981 | at Green Bay Packers (Milw) | W 30-13 | 55012.0 |
| 5.0 | October 4, 1981 | Chicago Bears | W 24-21 | 43827.0 |
| 6.0 | October 11, 1981 | at San Diego Chargers | W 33-31 | 50708.0 |
| 7.0 | October 18, 1981 | Philadelphia Eagles | W 35-23 | 45459.0 |
| 8.0 | October 25, 1981 | at St. Louis Cardinals | L 30-17 | 48039.0 |
| 9.0 | November 2, 1981 | at Denver Broncos | L 19-17 | 74834.0 |
| 10.0 | November 8, 1981 | Tampa Bay Buccaneers | W 25-10 | 47038.0 |
| 11.0 | November 15, 1981 | New Orleans Saints | W 20-10 | 45215.0 |
| 12.0 | November 23, 1981 | at Atlanta Falcons | L 31-30 | 54086.0 |
| 13.0 | November 29, 1981 | Green Bay Packers | L 35-23 | 46025.0 |
| 14.0 | December 6, 1981 | at Chicago Bears | L 10-9 | 50766.0 |
| 15.0 | December 12, 1981 | at Detroit Lions | L 45-7 | 79428.0 |
| 16.0 | December 20, 1981 | Kansas City Chiefs | L 10-6 | 41110.0 |
Question:
Tell me opponent for result of w 33-31
Answer:
at San Diego Chargers