Coming off their divisional home win over the Seahawks, the Cardinals flew to M&T Bank Stadium for an intraconference bird battle with the Baltimore Ravens.  In the first quarter, the Ravens flew first with kicker Matt Stover getting a 21-yard field goal for the only score of the period.  In the second quarter, the Ravens increased their lead with Stover's 28-yard field goal.  Arizona would manage to get on the board with kicker Neil Rackers getting a 48-yard field goal, yet Baltimore managed to put more and more distance from the Cards with QB Steve McNair completing a 13-yard TD pass to WR Derrick Mason, along with WR/PR Yamon Figurs returning a punt 75 yards for a touchdown. In the third quarter, the Cardinals managed to get a 40-yard field goal from Rackers, yet the Ravens continued its domination with Stover getting a 43-yard field goal.  In the fourth quarter, with QB Matt Leinart being ineffective, back-up QB Kurt Warner came in and ignited the Cards' offense with a 5-yard TD pass and a 32-yard TD pass to WR Anquan Boldin.  Afterwards, Arizona tied the game with Rackers getting a 41-yard field goal.  The Ravens got a last-second win with Stover nailing a 46-yard field goal.
Question: How many yards was the first field goal of the game?
Answer: 21