input: Write a function to find the word in the given document and return the line number where the word is found. If the word is not found, return -1. If the document is empty, return -1.
  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.', 'fourth') == -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