The Panthers started off their season by making their first return to Levi's Stadium since losing to the Denver Broncos in Super Bowl 50. Late in the first quarter Cam Newton threw a 40-yard touchdown to Russell Sheppard followed by a Graham Gano field goal. The Panthers scored six more points in the second quarter with two field goals. In the third Jonathan Stewart scored a touchdown, followed by another Gano field goal. With 3:14 left to go in the third quarter, Gano made his third field goal of the day making the score 23-0. Robbie Gould's kick with thirteen seconds to go gave the 49ers their first points of the game. Neither the Panthers or 49ers scored in the fourth quarter, resulting in Carolina defeating San Francisco 23-3. They improved to 1-0.
Question: How many points did the Carolina defeat San Francisco by?
Answer: 20