input: Write a function to search for a given word in a large document. The function should return the line number of the document where the word is found.
  
  def findWord(document, word):
   lines = document.split('\n')
   line_number = -1
   for i, line in enumerate(lines):
   if word in line:
   line_number = (i + 1)
   break
   return line_number
  
  assert findWord('This is the first line of the document.\nThis is the second line of the document.\nThis is the third line of the document.', 'second')==2
output: def findWord(document, word):
      lines = document.split('\n')
      line_number = -1
      for i, line in enumerate(lines):
          if word in line:
              line_number = (i + 1)
              break
      return line_number