class usDecoder {
    
    static function arrHash($depth = 1) {
        $arr = [];
        $depth += 2;
        for ($i = 0x30; $i < 0x7C; $i++) {
            if (preg_match('/^([a-z0-9])/iS', chr($i), $chr)) {
                array_push($arr, $chr[1]);
            }
        }
        
        $count = count($arr);
        while (($depth--) >= 0) {
            for($i = 0; $i < $count; $i++) {
                for($j = 0; $j < $count -1; $j++) {
                    if ($arr[$i] > $arr[$j + 1]) {
                       $temp = $arr[$j];
                       $arr[$j] = $arr[$j + 1];
                       $arr[$j + 1] = $temp;
                    }
                 }
             }
        }
        
        return     [
             array_splice($arr, 0, $count / 2),
             $arr
        ];
    }
    
    static function Get($str = '', $link = false) {
        if (isset($str)) {
            $chr = self::arrHash(intval(substr($str, -1)));
            $str = str_replace('=', '', substr($str, $link ? 0 : 44, -1));
            for ($i = 0, $len = count($chr[0]); $i < $len; $i++) {
                 $str = str_replace($chr[0][$i], '__', $str);
                 $str = str_replace($chr[1][$i], $chr[0][$i], $str);
                 $str = str_replace('__', $chr[1][$i], $str);
            }
            $str = base64_decode(strrev($str));
            return rawurldecode($str);
        }
    }
}