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: Gasoline-powered vehicles emit a lot of harmful materials. Nitrogen oxides are formed when atmospheric nitrogen reacts with oxygen at the high temperatures found in a car engine. Carbon monoxide is a by-product of incomplete combustion of hydrocarbons. Evaporated and unused fuel releases volatile hydrocarbons into the atmosphere to help form smog. The presence of a catalytic converter in the exhaust system of the car causes these materials to react and be changed into less harmful products.
Story: After decades of debate, Brunei decided to adopt electrical vehicles and use them extensively, ultimately phasing out gasoline powered vehicles. Their neighbor Nepal decided to continue using gasoline-powered vehicles extensively.
Question: Which country contributed to the formation of more nitrogen oxides?

Ex Output:
Nepal.

Ex Input:
Background Paragraph: Storing large volumes of data When storing XML to either file or database, the volume of data a system produces can often exceed reasonable limits, with a number of detriments: the access times go up as more data is read, CPU load goes up as XML data takes more power to process, and storage costs go up. By storing XML data in Fast Infoset format, data volume may be reduced by as much as 80 percent.
Story: Carl had a busy day storing XML. At 1 PM, he stored 1000 Gigabytes to the database. At 2 PM, he stored 2000 Gigabytes to the database. At 3 PM, he stored 3000 Gigabytes to the database. At 4 PM, he got dinner. At 5 PM, he stored 4000 Gigabytes to the database. At 6 PM, he stored 5000 Gigabytes to the database. At 7 PM, he went to sleep to finish storing XML tomorrow.
Question: What time did storage costs go up: 3 PM or 7 PM?

Ex Output:
3 PM.

Ex Input:
Background Paragraph: A mycorrhiza (Greek for "fungus roots") is a symbiotic association between a fungus and the roots of a plant. In a mycorrhizal association, the fungus may colonize the roots of a host plant by either growing directly into the root cells, or by growing around the root cells. This association provides the fungus with relatively constant and direct access to glucose, which the plant produces by photosynthesis. The mycelia of the fungi increase the surface area of the plant's root system. The larger surface area improves water and mineral nutrient absorption from the soil.
Story: Two friends studied permaculture together. Bill studied about mycorrhiza, while Red studied about hugel kultur.
Question: Which friend learned less about surface areas of root systems?

Ex Output:
Red.