input: Write a function to edit the given Python program to print 'Happy Holidays' 10 times instead of 'Hello World'. If the given program is empty, simply return the original string. If the given program does not contain the string 'Hello World' or 'Happy Holidays', return 'Invalid input'.
  assert edit_holiday_message("for i in range(10):\n    print('Hello World')")=="for i in range(10):\n    print('Happy Holidays')"
  assert edit_holiday_message("")=="Invalid input"
  assert edit_holiday_message("for i in range(10):\n    print('Greetings')")=="Invalid input"
  assert edit_holiday_message("for i in range(10):\n    print('Happy Holidays')")=="for i in range(10):\n    print('Happy Holidays')"
output: def edit_holiday_message(program):
      if 'Hello World' in program:
          return program.replace('Hello World', 'Happy Holidays')
      elif 'Happy Holidays' in program or program == "":
          return 'Invalid input'
      else:
          return 'Invalid input'