let paperY = [];

=

function setup() {

  createCanvas(windowWidth, windowHeight);

}

​

function draw() {

  background(222, 193, 115);

  for(let i = 0; i < paperX.length; i++) {

    noStroke();

    fill(0,0,0,20); // shadow

    rect(paperX[i] + 4, paperY[i] + 6, 20, 30);

    fill(255, 230, 0); // sticky note

    rect(paperX[i], paperY[i], 20, 30);

    fill(0, 0, 200);

    textAlign(CENTER);

    text(i, paperX[i] + 10, paperY[i] + 20);

  }

}

​

function mouseClicked() {

    paperX.push(mouseX);

    paperY.push(mouseY);

    console.log("how many papers: " + paperX.length);

}

​

function keyPressed() {

  if (keyCode === UP_ARROW) {

    paperX.pop();

    paperY.pop();

    paperL.pop();

  }

  if (keyCode === DOWN_ARROW) {

    paperX.shift();

    paperY.shift();

    paperL.shift();

  }

  console.log("how many papers: " + paperX.length);

}