function setup() {
  createCanvas(800, 400);
  background(220,190,20);
  
  drawCircle(width/2, height/2, 400);  
}

// function draw() {
//   background(220); 
// }

function drawCircle(x, y, radius) {
  
  fill(20, random(50,155), 20);
  ellipse(x, y, radius);
  
  if(radius > 2) { 
    
    
    radius *= random(0.95,0.99);
    //now the drawCircle() function calls itself recursively.
    // (as long as radius is greater than 2)
   // x = x - radius/2;
    drawCircle(x, y, radius);
    
  }
}