input: 
  def calculate_circle_area() -> None:
      """Prompt the user to enter the radius of a circle and calculate its area.
      Display the calculated area to the user.
      
      Example:
      >>> calculate_circle_area()
      Please enter the radius of the circle: 5
      The area of the circle is: 78.5
      """
  
output:     radius = float(input("Please enter the radius of the circle: "))
      area = 3.14159 * radius ** 2
      print(f"The area of the circle is: {area}")