>>> golf=lambda n:exec("global n;n+=str(n+1)!=str(n+1)[-2**n%~n::-1];"*n*n)
>>> golf(5)
Traceback (most recent call last):
File "<pyshell#23>", line 1, in <module>
golf(5)
File "<pyshell#22>", line 1, in <lambda>
golf=lambda n:exec("global n;n+=str(n+1)!=str(n+1)[-2**n%~n::-1];"*n*n)
File "C:\Python33\lib\idlelib\PyShell.py", line 60, in idle_showwarning
file.write(warnings.formatwarning(message, category, filename,
AttributeError: 'NoneType' object has no attribute 'write'