The Chargers contained the New England Patriots offense for a 1-point lead through three quarters before losing 23-14. After being held without a first down in the third quarter, the Patriots went ahead with a field goal in the fourth quarter, and capped the scoring with Tom Brady connecting with Julian Edelman for a 69-yard TD. San Diego was shut out in the second half. The win gave New England their 12th straight 10-win season, the second-longest such streak in NFL history. The Chargers led 14-3 after scoring twice within 2 minutes, 33 seconds in the second quarter. Floyd made a diving catch for a 15-yard TD, and safety Darrell Stuckey returned a fumble for a 53-yard score. After Patriots kicker Stephen Gostkowski's second field goal, Brandon Bolden blocked a punt by Scifres, and New England recovered the ball at the San Diego 28. Scifres was carted off the field after injuring his left shoulder on the play. Four plays later, Brady hit Rob Gronkowski on a 14-yard TD pass to trail 14-13. Before halftime, Te'o leaped for his first career interception on a pass intended for Gronkowski, preserving the Chargers' lead. In the third quarter, Devin McCourty returned a Rivers interception for a touchdown, but the play was wiped out by a personal foul on Brandon Browner for San Diego's Ladarius Green in the head. The Chargers' offense crossed midfield just once in the second half, getting as far as the Patriots 42. Their defense held New England to just 35 yards in the third quarter, forcing a three-and-out on four consecutive drives, before Brady engineered the 32nd fourth-quarter comeback of his career. Rivers completed 20 of his 33 passes for 189 yards. He fell to 0-6 against Brady, who was 28-of-44 for 317 yards and two touchdowns with one interception. The Patriots entered the game scoring an average of 31.5 points, the third highest in the league. Novak took over as punter after Scifres' injury; he filled in after starting with a couple of short kicks. Scifres required season-ending surgery for a  broken collarbone. Mathews entered the locker room early before halftime after limping following a tripping penalty by New England.  After rushing nine times for 52 yards in the first half, he had just two carries for minus 8 yards the rest of the game. The ankle sprain sidelined Mathews for the remainder of the season.
Question: How many passes did Philip Rivers throw?
Answer: 33