php, 46 bytes

Result

WA

Code [DL]

<?php $a=readline();sort($a);echo implode($a);

stdin

9184899433752579967497474772941057419848102046488558327073298452533343059803552344782021060111591816

stdout

stderr

PHP Warning:  sort() expects parameter 1 to be array, string given in /volume/CODE on line 1
PHP Warning:  implode(): Argument must be an array in /volume/CODE on line 1

strace