float cof = 75.0;  

void setup() {
size(500,500);
background(0);
}

void draw() {

for (int x = 0; x < 360; x++)
{
ellipse( 150 +cos(x)*cof,100+sin(x)*cof,16,16);
ellipse( 150 +cos(x)*cof,250+sin(x)*cof,16,16);

ellipse( 350 +cos(x)*cof,100+sin(x)*cof,16,16);
ellipse( 350 +cos(x)*cof,250+sin(x)*cof,16,16);
}

}