Definition: This task involves creating answers to complex questions, from a given passage. Answering these questions, typically involve understanding multiple sentences. Make sure that your answer has the same type as the "answer type" mentioned in input. The provided "answer type" can be of any of the following types: "span", "date", "number". A "span" answer is a continuous phrase taken directly from the passage or question. You can directly copy-paste the text from the passage or the question for span type answers. If you find multiple spans, please add them all as a comma separated list. Please restrict each span to five words. A "number" type answer can include a digit specifying an actual value. For "date" type answers, use DD MM YYYY format e.g. 11 Jan 1992. If full date is not available in the passage you can write partial date such as 1992 or Jan 1992. If you find multiple spans, please add them all as a comma separated list. Please restrict each span to five words.
Input: Passage: When the railroad was extended through Madison in 1875, larger mills were built. The first Madison Woolen Mill was constructed in 1881 near the bridge between Madison and Anson, with the firm's second mill built nearby in 1887. In 1890, the Manufacturing Investment Company built a sulfite mill, but it failed. It was taken over in 1899 by the Great Northern Paper Company, which rebuilt the plant to produce wood pulp and paper. Like many New England textile manufacturers, the town's woolen mills eventually went out of business, but the pulp and paper mill remains today as the Madison Paper Industries which will close by May 2016 due to low demand for supercalender paper and Canadian competition. In 1901, Lakewood Summer Theatre opened in East Madison on the western side of Lake Wesserunsett. Since 1967 it has been the official summer theatre of Maine, and the oldest continually operating summer theatre in America. Actors who have performed at Lakewood include John Travolta, Carol Channing, and Phyllis Diller Completed in 2007 is the largest structure by volume in Maine, the Backyard Farms greenhouse that covers 24 acres .
Question: How many years after the first Madison Woolen Mill was built was the second one built?
Answer type: Number
Output:
6.