Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Example Input: Context: Castigliano's method, named for Carlo Alberto Castigliano, is a method for determining the displacements of a linear-elastic system based on the partial derivatives of the energy. 
 Question: Who was the original discoverer of Castigliano's method?
Example Output: carlo alberto castigliano

Example Input: Context: Marino finished the game with 29 out of 50 pass completions for 318 yards, 1 touchdown, and 2 interceptions. Clayton was the top receiver of the game, with 6 receptions for 92 yards. Walker returned 4 kickoffs for 93 yards and gained 15 yards on 2 punt returns. Nathan was the Dolphins leading rusher with 18 yards, while also catching 10 passes for 83 yards. Craig had 58 rushing yards, 77 receiving yards, and 3 touchdowns. He was the first player ever to score 3 touchdowns in a Super Bowl, and his 2 touchdown catches also tied a Super Bowl record. Tyler led San Francisco in rushing with 65 yards, and also caught 4 passes for 70 yards. Clark caught 6 passes for 77 yards. Board recorded 2 sacks. McLemore recorded 51 punt return yards, the second most in Super Bowl history. Sports Illustrated called 49ers defensive tackle Gary Johnson (American football) the Super Bowls "unofficial defensive MVP" after he recorded one sack, flushed Marino out of the passing pocket numerous times, and had four unassisted tackles. 
 Question: Who had a higher average of yards per caught pass, Clayton or Clark?
Example Output: clayton

Example Input: Context: An interesting study posted on Facebook recently shows how men and women develop new interests as they mature . While women tend to take exercise seriously from the age of 34, men will wait until their 45th birthdays before working hard to get in shape. The average woman spends more time talking about sports, politics, career and money as she gets older. Women's interest in books reaches its peak at the age of 22, while that of men does so when they are in their 50s. Men start to change their focus from the workplace to other things after age 30, while women do not do so until eight years later. Both, however, care most about fashion at age 16. The research used anonymous data donated by thousands of Facebook users, recording the statuses, 'likes' and 'interests' they had posted on their profiles. It found the average woman talks about television most at 44, while men peak much younger, at age 31. Men are also most likely to see a film in a cinema at age 31, while women go out to see films most when they are only 19. Men are most interested in travel at 29, women at 27, while women talk most about food and drink at 35, and men at 38. And if you are middle aged, a safe topic for any audience is the weather, which is a key interest for many as they approach 60. Stephen Wolfram, the British scientist who carried out the research, says, "It's almost shocking how much this tells us about the changes of people's typical interests. "People talk less about video games as they get older, and more about politics." 
 Question: When do women love books best?
Example Output:
at the age of 22.