Getting an error while trying to open program with pyautogui

I'm trying to open notepad with pyautogui, but when trying to run code getting this kind of error:

Traceback (most recent call last): File "D:/Code/Python/AutoGui/autogui.py", line 10, in app = Application.start("notepad.exe") TypeError: start() missing 1 required positional argument: 'cmd_line'

Here is my code:

from pywinauto.application import Application
app = Application.start("notepad.exe")
app.UntitledNotepad.TypeKeys("%FX")

pyautogui was installed successfully without any errors. Using Python: 3.3.5