class Wanderer {
  float x, y;    // the position of the Wanderer
  
  // Initialize a Wanderer to be at the given coordinates
  Wanderer(float x0, float y0)
  {
    x = x0; y = y0;
  }
  
  // Draw a Wanderer, wherever it happens to be now
  void draw()
  {
    fill(255);
    ellipse(x,y,5,5);
  }

  // Update the state of a Wanderer  
  void update()
  {
    x+=random(-2,2);
    y+=random(-2,2);
  }
}