You are given a background paragraph that describes one or more causal or qualitative relationships such as a relationship in economics or a scientific law and a story that makes use of the concepts or the relationship described in the provided paragraph. You are also given a question about the story that requires an understanding of the relationship described in the background paragraph and the story. You need to come up with an answer to the given question; the answer will be a span from either the question or the story. In order to correctly answer the given question, you need to understand the relationship mentioned in the background paragraph and should be able to use it to understand that in the story. Your answer can not consist of any word that is not mentioned in any of these: the background paragraph, the story, or the question. You can directly copy and paste a span from the story or the question while answering the given question.

Ex Input:
Background Paragraph: Air pollution can also indirectly cause other health issues and even deaths. Air pollutants can cause an increase in cancer including lung cancer, eye problems, and other conditions. For example, using certain chemicals on farms, such as the insecticide DDT (dichlorodiphenyltrichloroethane) and toxic PCBs (polychlorinated biphenyl), can cause cancer. Indoors, pollutants such as radon or asbestos can also increase your cancer risk. Lastly, air pollution can lead to heart disease, including heart attack and stroke. 
Story: Two neighboring towns had different methods of growing crops. Lean town used insecticides, while Bean town did not. Lean town had high levels of air pollution. 
Question: Which town had more inhabitants experiencing heart attack?

Ex Output:
Lean.


Ex Input:
Background Paragraph: The water level is seasonal, being lowered by about 10 feet (3.0 m) over the winter. The reservoir fills in the spring from snow melt and underground springs. The lake is usually at full level by late spring, but in the occasional years of low snow melt and low rainfall, it may remain up to several feet below its typical level. Water is let out of the lake in the fall so that ice will not damage docks and other structures around the lake. This also leads to excellent water quality, as a significant portion of the water is replaced every year. 
Story: Bob has been wanting to go on vacation to the nearest lake in his area. He prefers to go to the lake when it is at it's highest level. He doesn't want to go during the summer, and has decided he must choose between the fall, and the spring for the best temperatures. 
Question: Will the spring water level be higher or lower than in the fall?

Ex Output:
higher.


Ex Input:
Background Paragraph: As shown here, pressure decreases to less than 25% of ground-level atmospheric pressure when we get to an altitude of about six miles. Since this is a common cruising altitude for commercial airplanes, pressurized cabins are needed for the comfort and survival of the passengers. This is because the density of the air decreases along with the decreasing air pressure, so there is less oxygen in a breath of air. You've probably noticed this effect in high-mountain areas, as it often feels harder to breath. 
Story: John likes to ride on hot air balloon. Last month he rode on a balloon with his friend Keith. First they were at the ground-level. They called it camp A. Then they rose to the height of three miles. They called it camp B. Eventually, they reached six miles above ground. They called it camp C. 
Question: Where the air would be denser, camp A or camp B?

Ex Output:

camp A.