Task: Question Answering
Input (English): Passage: Coming off their win over the Giants the Eagles flew to Soldier Field for an NFC duel with the Bears. The Eagles had the early advantage with kicker David Akers nailing a 45-yard field goal. It soon disappeared after QB Jay Cutler completed a 10 and a 20-yard TD pass to wide receivers Earl Bennett and Johnny Knox respectively. The Eagles tried to cut the lead with QB Michael Vick getting an 8-yard TD pass to WR Jeremy Maclin, followed by Akers hitting a 36-yard field goal. But they fell further behind as Cutler got a 6 and a 9-yard TD pass to Bennett and Greg Olsen. This was followed by kicker Robbie Gould making a 23-yard field goal. The Eagles tried to narrow the lead as Akers got a 22 and a 36-yard field goal, followed by Vick throwing a 30-yard TD pass to TE Brent Celek, but the Bears' defense prevented any more scoring chances. 
Question: How many yards longer was David Akers' longest field goal than his shortest? 
Answer type: Number 
Output (English): 23.