Definition: In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
Input: Passage: After the Nazis came to power, he emigrated to Switzerland in 1933 and to the United States later. He began his studies in Zurich and worked part-time as a house teacher. Meanwhile, he wrote articles and book reviews for the Neue Zurcher Zeitung, using several pseudonyms because of prohibition of work. He earned his PhD and taught French and German Literature at various universities, including Princeton University and University of Wisconsin-Madison. During a journey to Europe, Vordtriede was surprised by the outbreak of the Second World War and interned as an Enemy alien in occupied France. By interventions, he became free months later and was allowed to go back to America. He met his mother in New York City late in 1941, who also emigrated to the USA. He received the American citizenship in 1946 and became a Guggenheim Fellow in 1957. His sister Franze emigrated in 1947 and went to Philadelphia.
Link Information: Zurich. The municipality has approximately 409,000 inhabitants, the urban agglomeration 1.315 million and the Zurich metropolitan area 1.83 million Question: What is the population of the city where Vordtriede once studied and worked as a teacher?
Output:
Answer: metropolitan area 1.83 million