# Create a single-user version of the classic [https://en.wikipedia.org/wiki/Pong Pong] game: one paddle, controlled by the keyboard, and one single-pixel ball that bounces off the paddle plus the three sides of the screen not guarded by the paddle. The game is over if the ball hits the fourth side of the screen. (The screen may optionally have lines drawn on the three sides on which the ball bounces).