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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_id(page):
 """Extract the id from a page. Args: page: a string Returns: an integer """

  start_pos = page.find("<id>")
  end_pos = page.find("</id>")
  assert start_pos != -1
  assert end_pos != -1
  start_pos += len("<id>")
  return int(page[start_pos:end_pos])