In this task, you're given passages that contain mentions of the quantity of a particular object and are supposed to find out the answer for a given question. Craft one correct answer to the question given in input. Make sure your correct answer is consistent with the context, and properly gives the exact number relating to the query.
 In your answer, use as few words as possible from the given context. To be less repetitive, please vary your language for each question.
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Question: Sentence: The 21 nocturnes are more structured, and of greater emotional depth, than those of Field (whom Chopin met in 1833). Many of the Chopin nocturnes have middle sections marked by agitated expression (and often making very difficult demands on the performer) which heightens their dramatic character. 
Question: How many nocturnes did Chopin compose?

Answer: 21


Question: Sentence: Antibacterial-resistant strains and species, sometimes referred to as "superbugs", now contribute to the emergence of diseases that were for a while well controlled. For example, emergent bacterial strains causing tuberculosis (TB) that are resistant to previously effective antibacterial treatments pose many therapeutic challenges. Every year, nearly half a million new cases of multidrug-resistant tuberculosis (MDR-TB) are estimated to occur worldwide. For example, NDM-1 is a newly identified enzyme conveying bacterial resistance to a broad range of beta-lactam antibacterials. The United Kingdom's Health Protection Agency has stated that "most isolates with NDM-1 enzyme are resistant to all standard intravenous antibiotics for treatment of severe infections." 
Question: How many new infections of resistant TB are reported per year?

Answer: half a million


Question: Sentence: All of the highways into Wenchuan, and others throughout the province, were damaged, resulting in delayed arrival of the rescue troops. In Beichuan County, 80% of the buildings collapsed according to Xinhua News. In the city of Shifang, the collapse of two chemical plants led to leakage of some 80 tons of liquid ammonia, with hundreds of people reported buried. In the city of Dujiangyan, south-east of the epicenter, a whole school collapsed with 900 students buried and fewer than 60 survived. The Juyuan Middle School, where many teenagers were buried, was excavated by civilians and cranes. Dujiangyan is home of the Dujiangyan Irrigation System, an ancient water diversion project which is still in use and is a UNESCO World Heritage Site. The project's famous Fish Mouth was cracked but not severely damaged otherwise. 
Question: How many students out of the 900 in the school, survived the collapse?

Answer:
60