<?php
/**
 *  
 */
class Bmi 
{
	protected $weight;
	protected $height;

	function __construct($w,$h)
	{
		$this->weight = $w;
		$this->height = $h;
		
	}

   public function countBmi(){
    $bmi = ($this->weight)/(($this->height)*($this->height));
    return $bmi;
   }
   
}

class OldBmi extends Bmi{
private $howOld;
function __construct($w,$h,$o){
parent::__construct($w,$h);
$this->howOld = $o;	
}
public function getHowOld(){
	return $this->howOld;

}

}


$myObj = new OldBmi(80,1.80,65);


 $myBmi =  $myObj->countBmi();
 $howOld = $myObj->getHowOld();
 $correctBmi = $myBmi - $howOld/50;
 echo $correctBmi; 

?>