$product = array("a","b","c","d","e","f");
$p_count = count($product);
$free = 3;
foreach ($product as $key => $value){
$key++; 
 $uc = $key/$free;
 if(is_int($uc) && $uc != 0)
{ echo '<p>Bedava</p>'; }
else{ echo "<p>Paralı</p>"; } }