void setup() {
  size(700,500);
  background(0,0,0);
  
  
noFill();
 stroke(163,92,125);
 strokeWeight(2);
  for(int i=80/2; i<680; i+=82/2) {
     for(int j=80/2; j<480; j+=82/2) {
       ellipse(i, j, 82, 82);
  }
 }
}