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.

Input: Consider Input: Context: In the present study, we tested the hypothesis that having migraine in middle age is related to late-life parkinsonism and a related disorder, restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED). The AGES-Reykjavik cohort (born 1907-1935) has been followed since 1967. Headaches were classified based on symptoms assessed in middle age. From 2002 to 2006, 5,764 participants were reexamined to assess symptoms of parkinsonism, diagnosis of Parkinson disease (PD), family history of PD, and RLS/WED. Subjects with midlife migraine, particularly migraine with aura (MA), were in later life more likely than others to report parkinsonian symptoms (odds ratio [OR]MA = 3.6 [95% CI 2.7-4.8]) and diagnosed PD (ORMA = 2.5 [95% CI 1.2-5.2]). Women with MA were more likely than others to have a parent (ORMA = 2.26 [95% CI 1.3-4.0]) or sibling (ORMA = 1.78 [95% CI 1.1-2.9]) with PD. Late-life RLS/WED was increased for headache generally. Associations were independent of cardiovascular disease and MRI-evident presumed ischemic lesions. These findings suggest there may be a common vulnerability to, or consequences of, migraine and multiple indicators of parkinsonism. Additional genetic and longitudinal observational studies are needed to identify candidate pathways that may account for the comorbid constellation of symptoms.
Question: Willis-Ekbom disease is also known as?

Output: restless legs syndrome

Input: Consider Input: Context: The photo above represents water in three common states of matter. States of matter are different phases in which any given type of matter can exist. There are actually four well-known states of matter: solid, liquid, gas, and plasma. Plasma isnt represented in the iceberg photo, but the other three states of matter are. The iceberg itself consists of water in the solid state, and the lake consists of water in the liquid state. Q: Where is water in the gaseous state in the above photo? A: You cant see the gaseous water, but its there. It exists as water vapor in the air. Q: Water is one of the few substances that commonly exist on Earth in more than one state. Many other substances typically exist only in the solid, liquid, or gaseous state. Can you think of examples of matter that usually exists in just one of these three states? A: Just look around you and you will see many examples of matter that usually exists in the solid state. They include soil, rock, wood, metal, glass, and plastic. Examples of matter that usually exist in the liquid state include cooking oil, gasoline, and mercury, which is the only metal that commonly exists as a liquid. Examples of matter that usually exists in the gaseous state include oxygen and nitrogen, which are the chief gases in Earths atmosphere. A given kind of matter has the same chemical makeup and the same chemical properties regardless of its state. Thats because state of matter is a physical property. As a result, when matter changes state, it doesnt become a different kind of substance. For example, water is still water whether it exists as ice, liquid water, or water vapor. The most common states of matter on Earth are solids, liquids, and gases. How do these states of matter differ? Their properties are contrasted in the Figure 1.1. Click image to the left or use the URL below. URL: Properties of matter in different states. Q: The Figure 1.2 shows that a liquid takes the shape of its container. How could you demonstrate this? A: You could put the same volume of liquid in containers with different shapes. This is illustrated below with a beaker (left) and a graduated cylinder (right). The shape of the liquid in the beaker is short and wide like the beaker, while the shape of the liquid in the graduated cylinder is tall and narrow like that container, but each container holds the same volume of liquid. Q: How could you show that a gas spreads out to take the volume as well as the shape of its container? A: You could pump air into a bicycle tire. The tire would become firm all over as air molecules spread out to take the shape of the tire and also to occupy the entire volume of the tire.
Question: the only state in which matter has a fixed shape is

Output: solid.

Input: Consider Input: Context: Marriages improve after children grow up and move out,according to an academic study, which suggests an "empty nest" is not always a bad thing. Popular wisdom has it that parents' relationships may suffer once their young fly the coop, because they feel they have lost their purpose in life.However, a new study by researchers at the University of California, Berkeley, has found that many couples actually feel happier when their children leave home because they are able to enjoy spending time together. In total,123 American mothers born in the 1930s were tracked for 18 years and asked to rate their satisfaction levels shortly after marrying, when they were bringing up babies, once their children reached their teenage years and finally at age 61, when almost all had "empty nests". Although not all said they were happier in general, most claimed their marriages had improved since their children had left home. Researchers believe this is not just because the spouses were spending more time together, but because they were able to enjoy each other's company more. One of the participants in the study,which is published in the journal Psychological Science,said:"Once the kids grow up...there's some of that stress removed...that responsibility removed,so things are a little more relaxed." Psychologist Sara Gorchoff,who carried out the investigation,said: "The takehome message for couples with young children is 'hang in there'." Her coauthor Oliver John added:"Don't wait until your kids leave home to schedule quality time with your partner." However, Dr Dorothy Rowe,from the British Psychological Society,said the effects of living in an "empty nest" will depend on the parents' relationship with their children."If you're just waiting for them to leave home so you can get on with your life,then of course you'll be pleased to see them go," she said, "But if you've built your life around your children you'll be terribly lonely.For some parents,their world falls apart when their children leave."
Question: When did many couples feel happier according to the study?
Output: at age 61, when almost all had "empty nests".