// A class describing what a Wonderer is, including what he can do
class Wanderer {
  float x, y;    // the position of the Wanderer
  float r;       // the radius of the wonderer
  color c;       // the color of the wonderer
  
  // Initialize a Wanderer to be at the given coordinates
  Wanderer(float x0, float y0, float r0, color c0)
  {
    x = x0; y = y0; r = r0; c = c0;
  }
  
  // Draw a Wanderer, wherever it happens to be now
  void draw()
  {
    fill(c);
    stroke(red(c)/2,green(c)/2,blue(c)/2);
    ellipse(x,y,r*2,r*2);
  }

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