def find_layout_dimensions(boxes):
    """
    Find the dimensions of the smallest rectangle that fits
    all the boxes, starting from (0,0)
    """
    box_max_x = max(boxes, key=lambda box: box.x)
    max_x = box_max_x.x + box_max_x.width

    box_max_y = max(boxes, key=lambda box: box.y)
    max_y = box_max_y.y + box_max_y.height

    return (max_x, max_y)