input: Write a function in Python 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
  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.", "third")==3
  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.", "first")==1
  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.", "notfound")==-1
  assert findWord('', "any")==-1
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