human
Solve the following python programming problem given the following code:
# Example of a function:

def add_five(a):
  """This function adds the number five to its input argument."""
  return a + 5

# Let's try it out!
x = int(input('Please enter an integer: '))
print('Our add_five function is super effective at adding fives:')
print(x, '+ 5 =', add_five(x))
Given the above code, generate some markdown instructions for it.
assistant
#Here is the Python program you requested.

6. User defined functions
A function is a block of organized, reusable code that is used to perform a single, related action. Functions provide better modularity and a high degree of code reusing.
As we have seen, Python gives us many built-in functions like print(), etc. but you can also create your own functions.
Defining a function:

Function blocks begin with the keyword def followed by the function name and parentheses ( ( ) ).

Any input parameters or arguments should be placed within these parentheses. You can also define parameters inside these parentheses.

The first statement of a function can be an optional statement - the documentation string of the function or docstring. Docstring blocks start and ed with triple quotes (""").

The code block within every function starts with a colon (:) and is indented.

The statement return [expression] exits a function, optionally passing back an expression to the caller. A return statement with no arguments is the same as return None.