python3, 30 bytes

Result

WA

Code [DL]

print(''.join(sorted(read())))

stdin

2531779769783034760675202261055438617711761811533968131960689234835733249898978484612803297640139462

stdout

stderr

Traceback (most recent call last):
  File "/volume/CODE", line 1, in <module>
    print(''.join(sorted(read())))
NameError: name 'read' is not defined

strace