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: New species develop naturally through the process of natural selection . Due to natural selection, organisms with traits that better enable them to adapt to their environment will tend to survive and reproduce in greater numbers. Natural selection causes beneficial heritable traits to become more common in a population and unfavorable heritable traits to become less common. For example, a giraffe’s neck is beneficial because it allows the giraffe to reach leaves high in trees. Natural selection caused this beneficial trait to become more common than short necks. 
Story: Pam and Jill studied mammals. Jill was fascinated with their nutrition, while Pam was more interested and read about the natural selection phenomenon. 
Question: Which person studied more about organisms with traits that better enable them to adapt to their environment?

Ex Output:
Pam.


Ex Input:
Background Paragraph: About 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock. 
Story: White mountains are often visited by tourists because of the many beautiful caves, stalactites, stalagmites and karst phenomena. Dome mountains are interesting to tourists because they are very massive, of volcanic origin and excellent for climbing. 
Question: Which mountain has a higher percentage of limestone in its composition?

Ex Output:
White.


Ex Input:
Background Paragraph: There are two basic types of energy in the universe: potential energy and kinetic energy. Potential energy is stored energy that is available to do work, but it has not yet been released. The wood in a fireplace possesses potential energy. It is available for producing heat, but has not yet been ignited, so it is not releasing heat into the surrounding environment. Kinetic energy is the energy of motion. A waterfall is an example of kinetic energy. The moving water can erode the rocks in the stream, wearing them down into smaller particles. This same water motion can turn a turbine to generate electricity. In both cases, the movement of the material (water) causes work to be done. 
Story: While out on a hiking trip Ricky stumbles upon a waterfall. While looking at it he notices that the rocks around and behind the waterfall as well as the rocks in the stream it flows into are smooth, When he is no longer near the waterfall the rocks are very jagged and cracked and sharp. 
Question: Will the area near a water fall have sharp or smooth rocks?

Ex Output:

smooth.