$cash = 3300;
$summary = $cash;
$bills = array(
		100 => 23,
		500 => 5,
		1000 => 0,
		5000 => 77
		);
 
krsort($bills);	
echo "<pre>";
print_r($bills);
echo "</pre>";
$billSum = array();
	foreach ($bills as $key => $value){
		$billSum[$key] = $key*$value;
		}
		$amount = array_sum($billSum);
		echo "Доступно на данный момент: $amount <br>";
	    if ($cash > $amount) 
	    {
	       echo 'В банкомате недостаточно средств для выдачи денег<br>';
	    }
else { 
echo "Вам будет выдано: <br>";
foreach ($bills as $nominal => &$count)
{
 
	if ($value != 0)
	{ 
		$arg = floor($cash / $nominal);
		if ($arg > $count){
		$arg = $count;
		}		
		$sum = $arg * $nominal;
		$cash -= $sum;
		$count -= $arg;
		if ($arg != 0)	
		{
			echo "$arg купюр номиналом $nominal на сумму $sum <br>";
		}
		}
}
echo "Общая сумма: $summary<br>";
}
echo "<pre>";
print_r($bills);
echo "</pre>";

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