Problem Statement
Write a python script to print the docstring(documentation string) of the input function.

Instructions
Open the app.py file using vim editor vim app.py.
Press i to insert content in the file.
Write the required python code.
Press the Esc key, and type :wq in the editor to save the file.
Execute the script with command python3 app.py | tee output.txt.
Hint:
use help() function to get the docstring