int N = 400;
int numCircles = 200;

size(N,N);
background(255);
noStroke();

for (int j=0; j < numCircles; j++) {
  fill(random(255), random(255), random(255), random(127,255));
  float sz = random(0.2 * N);
  ellipse(random(N), random(N), sz, sz);   
}


save("randomCircles.jpg");