Looking for something in json file then trying something else if it doesnt work

Im getting json files from a site and i want it to find which ever one gets the file and use that one. Im using the $_GET Method too. There are 2 ways of getting the same file but they both require an id or a custom url from steam.

My url example: http://ift.tt/1DgKUNc

2 ways of getting json file:

• http://ift.tt/1KGINlV
• http://ift.tt/1DgM5wn

How im decoding it:

$id = $_GET['id'];
$url = "http://ift.tt/GFGALB".$id."/inventory/json/730/2";
$content = file_get_contents($url);
$playerinfo = json_decode($content, true);
$InventoryStatus = $playerinfo['success'];