<?php

class Planet
{
    static $instances = 0;
    public $instance;
    public $size;

    public function __construct()
    {
        $this->instance = ++self::$instances;
        $this->size = 25000;
    }

    public function __clone()
    {
        $this->instance = ++self::$instances;
    }

    public function getSize()
    {
        return $this->size;
    }
}

?>