function setup() {

  createCanvas(400, 400);

}

​

function draw() {

  let c = second()/2;

  background(220);

  console.log(c);

  if (c % 1 == 0.5) {

    noStroke()

    fill('red')

  rect(150,150,100,100);

}

    if (c % 1 == 0) {

  rect(150+c,150+c,100+c,100+c);

    }

}