Coming off their home win over the Rams, the Bengals flew to Bill Walsh Field at Monster Park for a Saturday night interconference duel with the San Francisco 49ers.  After a scoreless first quarter, Cincinnati trailed early in the second quarter as 49ers QB Shaun Hill got a 3-yard TD run.  Afterwards, the Bengals would take the lead as kicker Shayne Graham managed to get a 24-yard field goal, while QB Carson Palmer completed a 52-yard TD pass to WR Chris Henry.  San Francisco would end the half with Hill completing a 17-yard TD pass to TE Vernon Davis. In the third quarter, the 49ers increased their lead with kicker Joe Nedney getting a 29-yard and a 38-yard field goal.  In the fourth quarter, Cincinnati tried to respond as Graham kicked a 35-yard field goal.  However, the 49ers' defense held on for the win. With the loss, the Bengals fell to 5-9, securing Head Coach Marvin Lewis' first losing season with Cincinnati.
Question: How many yards was the longest touchdown pass?
Answer: 52