int casti = 400;

void setup(){
	size(500,500);
}

void draw(){
	for(int i=1; i<=casti; i++){
		fill(color(i%30,i%50+200,i%40+100));
		arc(250,250,400/casti*i, 400/casti*i, PI*2*i/casti, PI*2*i/casti+PI*2/casti); 
	}
}