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: 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.

Example Input: Background Paragraph: Soil is well developed in the forest as suggested by the thick humus layers, rich diversity of large trees and animals that live there. In forests, precipitation exceeds evapotranspiration which results in an excess of water that percolates downward through the soil layers. Slow rates of decomposition leads to large amounts of fulvic acid, greatly enhancing chemical weathering. The downward percolation, in conjunction with chemical weathering leaches magnesium (Mg), iron (Fe), and aluminum (Al) from the soil and transports them downward, a process known as podzolization. This process leads to marked contrasts in the appearance and chemistry of the soil layers. 
Story: Two  brothers were land owners. Bill owned 40 acres of forest, , with very well developed soil. His brother Rick owned 40 acres of grasslands, with a poor soil. Rick decided to sell his land. 
Question: Which brother owned a land which had slow rates of decomposition?
Example Output: Bill.

Example Input: Background Paragraph: Turner et al (2006) derived crash prediction models for this report’s predecessor and found a
pronounced ‘safety in numbers’ effect in the models. Using the crash prediction model for mid-block
locations, generic motorist and cyclist volumes can be used to demonstrate the impacts on the
expected crash rate of varying motor vehicle and cycle volumes. As shown in figure 2.20, an increase
in the proportion of cyclists to the overall traffic volume causes an increase in expected crashes at
mid-block locations, but the crash rate increases at a decreasing rate. That is to say, the crash rate per
cyclist goes down as the cycle volume increases. 
Story: There were a lot of motorcycles on Interstate 16 last week. On Sunday, there were 1255 motorcyclists. On Monday, there were 2255 motorcyclists. On Tuesday, there were 3251 motorcyclists. On Wednesday, there were 4251 motorcyclists. On Thursday, there were 5251 motorcyclists. On Friday, there were 6251 motorcyclists. On Saturday, there were 7251 motorcyclists. 
Question: What day had a lower crash rate per cyclist: Wednesday or Saturday?
Example Output:
Saturday.