class Cube {

  int xx;
  int yy;
  int xDir;
  int yDir;

  Cube (int x_, int y_, int xDir_, int yDir_) 
  { 
    xx = x_;
    yy = y_;
    xDir = xDir_;
    yDir = yDir_;
  }

  void move() {

    xx = xx + xDir;
    yy = yy + yDir;

    if (xx > width || xx < 0) {
      xDir = xDir * -1;
    }

    if (yy > height || yy < 0) {
      yDir = yDir * -1;
    }
  }

  void display() {
    move();
    fill(255,xx,yy);
    rect(xx,yy,5,150);
}
}