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.

Example Input: Background Paragraph: Predators play an important role in an ecosystem. For example, if they did not exist, then a single species could become dominant over others. Grazers on a grassland keep grass from growing out of control. Predators can be keystone species . These are species that can have a large effect on the balance of organisms in an ecosystem. For example, if all of the wolves are removed from a population, then the population of deer or rabbits may increase. If there are too many deer, then they may decrease the amount of plants or grasses in the ecosystem. Decreased levels of producers may then have a detrimental effect on the whole ecosystem. In this example, the wolves would be a keystone species. 
Story: Mike is studying the predator prey relationship. He is specifically studying three species, species A, species B, and species C. Species A is a predator; species B is the prey; and species C is a plant species that species B lives on. Mike now needs to figure out how the predator prey relationship balance the ecosystem. 
Question: If species C population decrease, would it affect the ecosystem positively or negatively?
Example Output: negatively.

Example Input: Background Paragraph: An equilibrium can also be disrupted by the full or partial removal of a reactant or product. If the concentration of a substance is decreased, the system will respond by favoring the reaction that replaces that substance. In the industrial Haber-Bosch process, NH 3 is removed from the equilibrium system as the reaction proceeds. As a result, the forward reaction is favored so that more NH 3 will be produced. The concentrations of N 2 and H 2 decrease. Continued removal of NH 3 will eventually force the reaction to go to completion until all of the reactants are used up. If either N 2 or H 2 were removed from the equilibrium system, the reverse reaction would be favored, and the concentration of NH 3 would decrease. 
Story: Jennifer and Justin are examining the principle of chemical equilibrium in their second year organic chemistry course. They are performing a reaction that involves hydrogen gas and glucose as the starting reactants, and the products formed in the reaction are carbon dioxide and oxygen gas. Jennifer and Justin add the materials, and then wait until the reaction has reached equilibrium. Afterwards, Jennifer removes glucose from her reaction mixture, while Justin removes carbon dioxide from his reaction mixture. 
Question: Which person's reaction, Jennifer's or Justin's, will begin producing more glucose?
Example Output: Jennifer's.

Example Input: Background Paragraph: You may hear males "ribbiting," producing a mating call used to attract females to the bodies of water best for mating and breeding. Frog calls can occur during the day or night. Each frog species has a different call that is used to attract mates and warn off rivals. When a female picks a male whose call she likes, the male grabs her and squeezes across her back and around her abdomen. This causes the female to release her eggs. The male then fertilizes the eggs and, in some species, also guards them. 
Story: Sandra liked all creatures but loved to study frogs. Her sister Julie studied more about fish and butterflies. They both loved nature. 
Question: Which sister learned more about different calls used by different species of frogs?
Example Output:
Sandra.